Survival Skills curriculum

The common version is three minutes without air, three hours exposed to harsh heat or cold, three days without water and three weeks without food. It is a memory aid for ranking needs, not physiology: cold shock in icy water can cause drowning within minutes, and being wet, in wind or in strong heat shortens the shelter and water figures. Use it to choose what to fix first, never as a countdown you can spend.

The order tracks how fast each threat can kill: heavy bleeding or a blocked airway in minutes, exposure in hours, dehydration in days, hunger in weeks. Army first aid controls life-threatening bleeding before opening the airway, unless a conscious person is choking. The Army survival manual keeps injury care first and reorders the rest by environment, putting fire and shelter before water in the cold. Signal whenever you can.

Hunger is loud and constant, so it pulls effort toward foraging and trapping while cold, wet and thirst do the real damage. You can last weeks without food, but not long in soaked clothes in the wind. Calories do matter in the cold, because they fuel shivering, yet getting dry and sheltered comes first. Where water is scarce, the Army survival manual's desert advice is not to eat at all.

STOP interrupts the urge to keep walking, which is what turns a wrong turn into a search. In the Forest Service version you stop and stay put, think back over how you got here, observe your compass and surroundings, then plan and act on one option. Its rule for the last step: unless you are very confident of the route, or if night is falling or you are hurt or near exhaustion, stay put.

Fear sets off a fight-or-flight surge: faster breathing, tense muscles and a pull toward tunnel focus on small tasks. That helps you sprint and hurts you when the job is judgment, which is why the Forest Service calls panic your greatest enemy. Slowing down on purpose restores choice: sit, breathe slowly and hold big decisions until the shock passes, as fire crews do with a tactical pause.

Hours of driving and miles already hiked make turning back feel like waste, but none of that changes the danger ahead; only conditions do. Wildland fire training calls the pattern escalation of commitment, accepting more risk as the goal gets close. Judge the next step on its own terms, and keep a backup plan so that turning around trades one outing for another instead of for nothing.

Fixation on reaching the top narrows attention until warnings stop registering: the late hour, building clouds, a partner slowing down. Wildland fire training lists it as target fixation, locking onto a course of action and just pushing harder. The guard is a decision made before you start, a turnaround time or weather trigger that ends the attempt on its own, so it is never argued in the moment.

Each person who splits off becomes a separate search, and the group loses the gear and skills it was sharing. NPS guidance is to set a pace that leaves no one behind and send a buddy with anyone who leaves. If someone goes missing, regroup at their last known spot instead of fanning out off trail, which makes more lost people. For an injury, send two or more for help while the rest stay.

The choices that prevent an emergency are made at home and cost little: a trip that fits your skills and fitness, a check of the forecast and alerts, the essentials packed and a trip plan left with someone. Once you are lost or hurt, every option is slower and harder, and NPS warns rescue can take hours or days. The Forest Service calls advance planning your best survival tool.

A moving person is harder to find, while searchers start from your planned route and last known point. NPS advice is to stay put once you have called for help, moving only if staying threatens your life. The Army survival manual allows travel when water, shelter and help are surely reachable, or after several days with no rescue and the gear to travel. The inner Grand Canyon expects self-rescue.

Searchers begin with your trip plan and last known position, so a change nobody knows about sends them to the wrong place. If you must leave a spot, a note there or on your vehicle saying when you left, which way you went and why moves the search's starting point with you. Sign trailhead registers, and tell your trusted contact whenever the plan changes.

Before acting, take honest stock: who is hurt and how badly, what each person carries, how much water and food remain, what the weather is doing and how much daylight is left. Listing it turns panic into a plan and often shows the real limit is not what feels urgent. The Army survival manual says to see things as they are, not as you want them; NPS says to check and conserve your essentials.

Weather sets deadlines you cannot bargain with: a thunderstorm brings lightning, rain upstream can flood a dry canyon, and a winter storm can close roads and cut visibility. The Forest Service advises considering leaving as a thunderstorm approaches, and Ready.gov treats a winter storm warning as the signal to find shelter right away. Plan every other task around that clock.

A trip plan works only if someone not on the trip holds it and knows when to act: your route, what you are doing, who is with you and a set time to call authorities if you have not checked in. Without one, an absence can go unnoticed; the FAA's aviation manual cites an Air Force review finding about 36 hours usually passed before family concern raised an alert.

A compass you cannot use, a fire starter you have never struck and a GPS you cannot read are dead weight that feels like safety. NPS guidance is to learn your navigation tools before you go and to practice with your essentials, and the Army survival manual calls the metal match its most useful fire starter only when the user is trained in it. Test new gear at home, where failure costs nothing.

Start from sunset and subtract: the time to get back, a margin for slower travel when tired, and time to make camp if you are delayed. The Forest Service advises starting early so you can return before dark, and Grand Canyon guidance budgets a third of your time for the descent and two thirds for the climb out, because the return there is the slower half. Carry a light in case the margin runs out.

Effort spent now draws on water and calories you may not be able to replace. Grand Canyon guidance gives simple gauges: walk at a pace where you can still talk, take a ten-minute break at least every hour, and eat more than usual, with salty snacks and water or a sports drink on any hike over 30 minutes. Huffing and puffing means you are burning reserves too fast.

When you cannot tell which choice is right, prefer the one you can undo. Waiting an hour, staying on the trail or retracing known ground can be reversed; dropping into a canyon or descending past where you could climb back cannot. Forest Service guidance for the lost applies the same logic: do not move until you have a specific reason to, and if you are not very confident of the route, stay put.

A turnaround time is set at home, in calm conditions, so fatigue and the pull of the goal get no vote later. Work it back from sunset or the weather window, allowing more time for a return that climbs. When the time comes you turn around wherever you are, near the top or not. Wildland fire crews use the same idea as trigger points: conditions set in advance that force a re-evaluation.

Groups drift toward the plan nobody questions, because disagreeing feels rude. Wildland fire training names it groupthink, being afraid to speak up or disagree, and counters it with norms: everyone has the right and the obligation to raise a safety concern, anyone can ask when unsure, and respectful disagreement is normal. Agree beforehand that one person's concern triggers a pause.

When everyone improvises at once, some tasks get done twice and others not at all. One coordinator assigns jobs, sets priorities and keeps everyone informed while still listening. Wildland fire leaders brief three things so people can act without constant direction: the task, its purpose, and what done looks like. The Army survival manual has the senior person lead a group on the move.

Rate each hazard by how likely it is and how bad it would be. A likely but minor problem, like blisters, needs a routine fix; an unlikely but catastrophic one, like a fall from an exposed ledge, can still justify changing the plan. The wildland fire risk process weighs probability against severity, adds controls, then weighs remaining risk against gain, and restarts when conditions change.

Each time a shortcut works, such as skipping the forecast, leaving the map behind or starting late, it feels more normal, and the margin you gave up stops being noticed. Getting away with it is not proof it was safe; the bad outcome may just have been unlikely that day. Wildland fire training flags the attitudes this breeds, complacency and "it can't happen to us."

The list is ten systems, not ten items, and NPS credits it to The Mountaineers. Each covers a failure: getting lost, darkness, sun, injury, broken gear (the knife sits under repair kit and tools), needing fire, a night out, and running short of food, water or warmth. Scale each to the trip, and count a phone as none of them, since its service and battery may both fail.

Anything you cannot do without needs a backup that fails for a different reason. A phone map and a phone GPS share one battery, so they count as one system; a paper map and compass do not depend on it. The same logic applies to fire, with a lighter and a ferrocerium rod, and to light, with spare batteries. NPS advises always carrying a backup paper map, because a phone can die, break or get lost.

Each route has its own fix. Radiation leaves exposed skin, so cover head, neck and hands. Convection strips the warm air layer next to you, so block wind. Conduction flows into whatever you touch, so get off cold ground and out of wet clothes. Evaporating sweat cools you, so vent before your layers soak. Breathing cold, dry air costs heat and water too.

Still air insulates, but the ground is dense, often damp and pressed against you by your full weight, so it pulls heat out faster than the air does. That is why sitting or lying on bare earth, rock or snow chills you even on a calm day. Anything between you and it, such as a pad, a pack, or a thick layer of boughs or dry leaves, reduces the loss.

Insulation works by trapping still air, and whatever lies beneath you is crushed by your weight and loses much of its loft. A heavier blanket on top cannot stop heat draining into the ground, while a pad resists compression, which is why it does more for a cold night. Improvised bedding must start thick: the Army survival manual calls for at least 12 inches of natural material.

Water fills the air spaces that let fabric insulate, then conducts heat away; the Army survival manual puts wet clothing's heat loss at up to 25 times that of dry, depending on fabric, and CDC gives the same multiple for wet feet. That is why soaking can bring on hypothermia in mild weather: NWS notes it can occur at temperatures as warm as 60°F, especially in water. Change into dry layers early.

Cotton soaks up water and collapses; the Army survival manual says it loses about 90 percent of its insulation value when wet. Wool stays warm when damp and synthetics resist absorbing water, which is why CDC lists them, not cotton, for cold-water survival. The rule is about cold: in hot, dry desert the same wet cotton helps, and Grand Canyon rangers recommend soaking it to stay cool.

Each layer has one job. The base moves sweat off your skin, which polypropylene and wool do and cotton does not. The middle traps still air for warmth. The shell blocks wind and rain so the others stay dry. Several thin layers beat one thick garment because each gap adds dead air and you can shed or add one to match effort. Keep them loose; tight clothing restricts circulation.

Sweat soaks your insulation from the inside, and once you stop moving that dampness chills you fast. The fix is to vent before you start sweating, not after: open the jacket, push back the hood, take off a layer or heavy mittens as you start to climb, and add them back the moment you stop. NWS warns that sweating from hard work in the cold can lead to a chill and hypothermia.

A good site removes hazards you cannot fix later. Look up for dead trees and loose limbs that can fall in wind or under snow. Stay above high-water marks and out of flash-flood paths, and away from avalanche, rockslide and mudslide runouts. Avoid low hollows where cold, dense air pools at night. Choose ground large and level enough to lie down with your gear.

In most improvised shelters your body is the only heater, and every extra cubic foot is air it must warm and surface it loses heat through. Build just big enough to lie down with your gear, or to sit up in a snow cave, and no bigger. A roomy shelter feels better while you build it and colder at night, and smaller also saves material and energy.

Start with what is already there: a rock overhang, a fallen tree, low conifer branches or a tree well can save hours of work. A lean-to makes a fast windbreak, its back set to the wind, and pairs well with a fire and reflector in front. A debris hut holds body heat: a body-sized frame piled with leaves or needles at least 3 feet deep, with a thick layer inside.

Snow insulates well, so a snow cave or tree-pit shelter holds body heat far better than open air, though digging one is slow and gets you wet. The danger is sealing it too well: candles, fuel gel and small lamps give off carbon monoxide, so keep a roof vent open and often one at the door. The Army manual's check: if you cannot see your breath, it is too warm and will start dripping.

The order follows what stops heat loss fastest. Get out of wind and wet first, add dry insulation all around, underneath included, then add heat. A warm, sweet, non-alcoholic drink cannot rewarm someone alone, but its sugar fuels shivering; give drinks only to someone fully conscious. Stripping wet clothes in wind can cool a person faster, so reach shelter before you change them.

The warm flush after a drink is misleading. A review of accidental hypothermia lists intoxication among factors that speed cooling by blunting shivering and the narrowing of skin blood vessels that keeps heat in the core. NWS notes alcohol reduces shivering, NPS says it increases heat loss, and CDC says not to give it to someone with hypothermia. It also dulls the judgment you need.

Your body has to melt snow and then warm the water to core temperature, and that energy comes from the heat and calories you are trying to keep; NWS warns that eating unmelted snow lowers body temperature. Melt it first, in a pot by the fire, in a bottle between clothing layers, or on dark cloth in the sun. Adding a little water to the pot first speeds the melting.

Wind strips away the thin warm air layer your skin builds up, so exposed skin loses heat faster than the thermometer suggests. NWS's example: at 0°F with a 15 mph wind, the wind chill is -19°F and bare skin can freeze within 30 minutes. The index applies only to people and animals, at 50°F or below with wind over 3 mph, and frostbite still needs actual air below freezing.

A stuck car is shelter, a visible target and your supplies in one place, and NWS warns that leaving it in wind-driven snow disorients you quickly. Run the engine about 10 minutes each hour for heat, clear snow from the exhaust pipe and crack a window to keep carbon monoxide out. Use the dome light at night while running, tie bright cloth to the antenna, and raise the hood once snow stops.

The umbles track a cooling brain and muscles: stumbles and fumbles are lost coordination, mumbles is slurred speech, and grumbles is a shift in mood and judgment. The person affected often cannot see these changes, so watch each other; NPS lists slurred speech, trembling, stumbling and impaired judgment as early signs. Treat the first umble as the signal to stop and warm up.

Pack it before the season, since a winter storm can last hours or days. Ready.gov's car kit covers getting moving (jumper cables, and sand for traction), light, warmth from spare clothes and blankets, and bottled water with snacks that keep, plus a full tank. NWS adds a charged phone and charger, first aid, an ice scraper, hand warmers, and a gallon of water a person each day for at least three days.

Clinicians stage it mainly by consciousness. In the Swiss system used in mountain rescue, stage I is awake and shivering at a core of 35 to 32°C; stage II has impaired consciousness, with or without shivering; stage III is unconscious with vital signs present; stage IV has none. Since a core thermometer is rarely at hand outdoors, the slide from alert to confused is the marker that matters.

Shivering is the body's main heater, so its fading is not recovery. A mountain-rescue medicine review says shivering stops when energy stores run out, core temperature drops below a person's threshold or consciousness is impaired, and that then little rewarming occurs and cooling can speed up. NPS treats ceased shivering, a sharp drop in mental status and a core below 90°F as severe hypothermia.

Frostbite often starts with redness or pain, then the tissue turns numb and white, grayish-yellow or waxy, and may feel unusually firm. The trap is that numbness removes the warning, so a spot that stopped hurting gets ignored, and numb skin burns easily near a stove or fire. Check the usual targets, nose, ears, cheeks, chin, fingers and toes, on each other, since you cannot see your own face.

Thawing frozen tissue and letting it freeze again does more harm than leaving it frozen longer, so the field question is whether you can keep it warm once thawed. Wilderness medicine guidance is to keep the part frozen until a thawed state can be maintained and to protect it from further injury. Never rub it or warm it at a fire, where numb skin burns, and avoid walking on frostbitten feet.

Trench foot is a nonfreezing injury: feet kept wet and cold lose heat so fast that the body clamps down blood flow to them, and the starved tissue begins to die. CDC says it can develop even at 60°F if feet stay wet. Watch for redness, numbness, tingling pain, swelling and blisters. Prevention is simple: change into dry socks through the day, and wash and dry your feet daily.

The first danger is not hypothermia. Sudden immersion triggers cold shock, an involuntary gasp and rapid breathing that can pull in water in the first minutes, plus a spike in heart rate and blood pressure; NWS notes the gasp can start in water as warm as 77°F. Next, cooling muscles lose control and swimming fails. Hypothermia, a core below 95°F, comes later. A life jacket buys time.

The memory aid gives about one minute to get breathing under control, about ten minutes of useful movement, and up to an hour before cold causes unconsciousness. Treat these as rough phases, not a schedule: NWS describes gasping that lasts two to three minutes or more and muscle loss that starts within seconds and worsens. Spend the first minutes on breathing and a plan, not a frantic swim.

If you cannot swim to safety, holding still conserves heat better than thrashing, which keeps flushing cold water past your skin. The H.E.L.P. posture, from Coast Guard guidance NWS repeats, draws knees to chin with legs together and presses arms to your sides, protecting critical body areas. In a life jacket it lets you float still while you wait. With others, huddle instead.

If you break through, turn back toward the way you came, since that ice already held you. Get your arms onto the unbroken surface, kick your legs to bring your body level, and work forward, digging in ice picks if you carry them. Once out, do not stand: lie flat and roll away from the hole to spread your weight. Keep winter clothes on, since they trap air for warmth and flotation.

NWS frames it as three ingredients: a slope generally steeper than 30 degrees; an unstable snowpack, often loaded by recent weather; and a trigger, which in 90 percent of incidents is the victim or their party. Warning signs include recent slides, shooting cracks, whumpfing, heavy snow or rain in the past day and rapid warming. Check your avalanche center and carry transceiver, shovel and probe.

Direct sun adds radiant heat on top of the air temperature, so moving into shade cuts your heat load at once, before any water is drunk. Grand Canyon rangers note that temperatures in full sun run well above posted shade temperatures. Put something between you and hot ground as well, as the Army survival manual advises, and rest in shade through the hottest hours instead of pushing on.

Most people needing emergency help for heat illness in Grand Canyon were hiking between 10 a.m. and 4 p.m., so rangers advise a predawn start, a midday rest in shade near water and a late finish. The Army survival manual likewise says to rest by day and work in the cool of evening and night. Desert nights cool fast, so carry warm layers and a flashlight.

Evaporating sweat is how you shed heat, and the price is water: Grand Canyon rangers say hikers can lose one to two quarts an hour. In dry air sweat vanishes almost as fast as it forms, so heavy losses go unnoticed; salt rings on clothing are a clue. You cannot safely stop sweating, but you can lower how much you need by cutting effort, staying in shade and soaking your clothes when water allows.

Drinking to need means matching intake to loss: sip regularly rather than gulping at stops, and watch your urine, aiming for steady output that is not dark. Thirst lags behind need, especially in older adults, so do not wait for it. Rationing to stretch a supply fails because dehydration impairs you long before the bottle is empty, while forcing water without salt risks hyponatremia.

Sweat carries sodium as well as water, so replacing hours of heavy sweating with plain water alone can leave your blood diluted. Grand Canyon guidance pairs water with some electrolyte replacement and salty snacks, which help your body hold fluid. NWS advises against salt tablets unless a physician specifies them, so food and sports drinks are the usual route.

Hyponatremia is blood sodium diluted by heavy water drinking while sweat removes salt. Its early signs, fatigue, nausea, vomiting and confusion, mimic heat exhaustion, and the urge to push more water makes it worse. Grand Canyon rangers note clues such as frequent urination and seeming intoxicated, and advise stopping water, eating salty food, resting in shade and getting help if alertness drops.

Working muscles make heat, so in hot conditions your pace is a cooling control as much as a speed choice. Slow down, break effort into shorter bouts with rests in shade, and move hard work to the coolest part of the day, as both NWS and OSHA advise. If you are breathing too hard to talk, you are producing heat and losing water faster than you can shed or replace them.

Hot ground radiates and conducts heat into whatever lies on it, so desert shelter is about distance from the surface as much as shade. The Army survival manual suggests a raised bed or a floor dug 18 inches down, which it says can cut shelter temperature by up to 40°F, and a double roof with a 12 to 18 inch air gap. Build in the cooler hours to save water.

Open desert offers few distinct landmarks, and the ones you see mislead. Distances fool the eye: the Army survival manual's rule of thumb is that something that looks 1 kilometer away is really about 3. Heat shimmer near the ground blurs shapes, which it suggests countering by climbing at least 10 feet above the desert floor. In a sand or dust storm, stay put rather than walk blind.

Sunlight reflected off snow, and also off water or other bright surfaces, can cause snow blindness: red, scratchy, watery eyes, headache and pain in bright light. Prevent it with UV-rated sunglasses, or improvised eye shades if you have none, and soot under the eyes cuts glare. The Army survival manual's treatment is to cover the eyes with dark cloth until the symptoms pass.

Your temperature is a balance: heat comes in from sun, hot air and hot surfaces, is made inside by working muscles, and leaves mostly as sweat evaporates. OSHA lists the factors: activity, air temperature, humidity, sunlight, heat sources such as hot roofs and roads, air movement and heat-trapping clothing. Cut the inputs you control, effort and sun, since humidity can close the main exit.

Repeated days in the heat train your body to cope, so the riskiest days are the first few in a hot place or after time away. OSHA's advice for those first days is shorter efforts, frequent breaks, enough fluids and fast attention to symptoms, and NWS applies the same gradual ramp to workers away a week or more. The Army survival manual adds that acclimated people need less water.

Sweat cools you only when it evaporates. In humid air it drips off instead, so you keep losing water without shedding much heat, which is why the same temperature is more dangerous when humid. It is also why NWS warns that a fan blowing on someone can make them hotter once the heat index is above the 90s. Dry desert air is the reverse: sweat evaporates so fast you may not notice how much you lose.

Sunlight on bare skin adds heat and burns, and NWS notes sunburn itself reduces your ability to shed heat. Loose, lightweight, light-colored clothing reflects sunlight and lets air move, while long sleeves, long pants and a wide-brimmed hat keep the sun off. In dry heat, a wet cotton shirt or bandana becomes an evaporative cooler, which Grand Canyon rangers recommend whenever you pass water.

A parked car works like a solar oven: sun heats the dashboard and seats, which NWS says can reach 180°F to over 200°F, and they heat the trapped air. Even on mild days in the 70s the inside can climb to dangerous levels quickly, and leaving windows cracked barely slows it. Never leave a child, pet or anyone vulnerable inside, and check that everyone is out each time you arrive.

Heat cramps, painful spasms usually in the legs or abdomen during heavy sweating, may be the first sign of heat illness and can lead to heat exhaustion or stroke, NWS warns. Treat them as a signal to stop and cool down, not to push through: rest in shade, press or gently massage the muscle, and sip water unless nauseated. Get medical help if cramps last over an hour.

Heat exhaustion comes from heavy sweating: weakness, fatigue, headache, nausea or vomiting, dizziness, cramps, and cool, pale, clammy skin. The person still thinks clearly, and that is the dividing line, since confusion means heat stroke. Grand Canyon rangers advise resting in shade for 30 to 45 minutes, drinking water with electrolytes and getting wet. Untreated, it can lead to heat stroke.

Altered mental status, such as confusion, slurred speech, odd behavior, seizures or collapse, separates heat stroke from heat exhaustion and means the body can no longer cool itself. Do not wait for dry skin: OSHA lists heavy sweating or hot, dry skin, so a sweating person can still have heat stroke. NWS notes body temperature above 103°F. Cool them at once while someone calls for help.

A dry wash is a drainage channel, and it can flood from a storm miles away under sunny skies. Water can rise within minutes or seconds, and Zion rangers say most flash-flood deaths come from debris strikes. Watch for building clouds, thunder, water turning muddy, floating debris or a rising roar upstream. If it starts, drop your gear and climb; six inches of moving water can knock you down.

When heat stroke is possible, cooling comes first, because delay can be fatal. OSHA calls immersion in cold water or an ice bath the fastest emergency method; otherwise pack ice or cold, wet cloths against the neck, armpits and groin, plus the head and trunk, and fan the person. Do not stop to work out which heat illness it is. When in doubt, cool and call 911 at the same time, and never leave the person alone.

A sunburn is more than sore skin when you are exposed: NWS notes it reduces your ability to get rid of heat, so later hours in the sun get riskier. Prevent it: seek shade when the sun is strongest, 10 a.m. to 4 p.m., wear long sleeves and a wide-brimmed hat, and use broad-spectrum SPF 30 or higher, reapplied every two hours. Water and sand reflect extra sun.

The heat index estimates how hot it feels once humidity is counted, because moist air slows sweat evaporation. NWS's example: 96°F at 65 percent humidity feels like 121°F. Two cautions apply. The index assumes shade and light wind, and full sun can add up to 15°F. For people working or hiking in the sun, NWS points to wet bulb globe temperature, which also counts wind and solar radiation.

Protozoa such as Giardia and Cryptosporidium are the largest: a filter rated 1 micron or smaller stops them, but chlorine and iodine work poorly on them. Bacteria need a filter of 0.3 micron or smaller, and disinfectants kill them. Viruses pass through portable filters except reverse osmosis, but disinfectants kill them too. Boiling handles all three, which is why CDC ranks it first.

A rolling boil means vigorous bubbling that keeps going, not the first wisps of steam. CDC calls for one minute at a rolling boil, or three minutes above 6,500 feet, since water boils at a lower temperature at altitude. EPA sets its three-minute cutoff lower, at 5,000 feet, so between those heights the longer boil is the cautious choice. Settle or strain cloudy water first.

A filter strains organisms by size, so its rating decides what it stops. CDC says a filter whose absolute pore size is 1 micron or less removes protozoa like Giardia, one at 0.3 micron or less also removes bacteria, and only reverse osmosis models remove viruses, so add a disinfectant after filtering. The Army survival manual warns that cracks or a frozen element can let organisms through.

Chlorine and iodine kill bacteria and viruses when dose and wait time are right. EPA's bleach dose is 8 drops of 6 percent bleach per gallon, left 30 minutes, with a faint chlorine smell afterward; if none, dose again and wait 15 more minutes. For 2 percent iodine tincture it is 5 drops per quart, 30 minutes. CDC says to avoid iodine if pregnant or with thyroid problems.

Disinfectants work less well in cloudy water and more slowly in cold water, so murky, colored or very cold water needs more. CDC and EPA both say to double the bleach dose for such water, and the Army survival manual extends the wait from 30 to 60 minutes when water is cold and cloudy. Neither chlorine nor iodine reliably kills Cryptosporidium, and no dose fixes fuel or heavy metals.

CDC says portable UV units handle protozoa, bacteria and viruses, but only in small batches of clear water. Particles shade germs from the light, so filter or settle cloudy water first, and a battery pen is useless once the battery dies, so carry a backup method. In a pinch, CDC describes solar disinfection: clear water in clean, clear plastic bottles in sun for 6 hours, or 2 days if cloudy.

Sediment shields germs from chlorine and UV and clogs filters, so clear the water before treating it. Let it stand so particles settle and pour off the clear top, or pour it through a coffee filter, paper towel or clean cloth. This improves the water, not its safety: settled or strained water still needs boiling, disinfecting or filtering. Charcoal can help remove odor.

Rain is among the cleanest water you can collect, but it picks up whatever is on the surface it runs across. Catch it in clean containers, tarps or ponchos, and let the first runoff wash dust and debris off the catchment before you start keeping water, which is the first-flush idea; the Army survival manual uses at least 15 minutes of rain over leaves. Treat collected runoff whenever you can.

Melt snow or ice before drinking it, since eating it frozen costs body heat. Melted snow is not automatically safe: the Army survival manual notes that frozen water is only as clean as the water that froze, so treat the meltwater as you would any wild water when you can. Gather clean, fresh snow, and prefer ice when you can find it, since it is the more concentrated source.

These methods work, but slowly. Walking through dewy grass with cloth tied around your legs, then wringing it out, yields about a quart by the Army survival manual's figure. A plastic bag sealed over a leafy branch collects water the plant gives off; empty it before sundown. Both require knowing the plant is not poisonous, and neither replaces what you sweat out working hard.

The classic still, a plastic sheet over a pit with a container under its low point, does draw water from damp soil or cut plants and can separate fresh water from salty or polluted water. The catch is yield against cost: digging a hole about 3 feet across and 2 feet deep spends sweat, and the Army survival manual says one person needs three or more stills and the return may not justify the effort.

Urine is how the body dumps waste and excess salt, so drinking it hands that load back to kidneys already short of water; the Army survival manual puts urine at about 2 percent salt. As dehydration deepens, urine turns darker and more concentrated, so the trade only gets worse. The manual groups it with seawater, blood and alcohol as things never to drink in place of water.

Water collects low and shows itself through life. Look for green vegetation in dry country, the outside bends of dry streambeds, the foot of cliffs and rock outcrops, and damp sand where digging may reach a seep. The Army survival manual adds animal clues: grazing animals are better guides to water than predators, and bees rarely fly more than four miles from their hive. Treat whatever you find.

Boiling kills all three classes of germs, including the Cryptosporidium that chlorine and iodine can miss, which is why CDC calls it the best method. Its limits are fuel and what it cannot remove: heavy metals, salts and most other chemicals stay in the pot. Settle cloudy water first, keep a rolling boil at least a minute, and pour it between clean containers to fix the flat taste.

Rank sources by how likely they are to be contaminated, then treat whatever you choose. Rain caught directly and water inside plants are usually cleanest, springs are typically the safest open source, then flowing streams, and still, stagnant water is the worst. EPA adds: skip water with floating material, a dark color or a questionable odor. Clear water can still carry germs.

Still water lacks the flow and oxygen that keep moving water comparatively cleaner, so waste, runoff and debris build up in it. The Army survival manual warns that water in natural depressions is often heavily contaminated, including with pesticides and garbage, and that stagnant tropical water can carry blood flukes. Boiling or filtering handles germs, not chemicals, so choose moving water.

Two kinds of contamination need different answers. Animal and human waste from livestock, wildlife or camps upstream carries germs that boiling, filtering and disinfecting can handle. Chemicals from mining, fuel or farm runoff cannot be boiled out; EPA notes old mine drainage can be acidic and rich in heavy metals. Look upstream before you fill up, and avoid water likely to be chemically polluted.

Clear, cold, fast water looks safe and often is not: CDC notes germs can be in water that looks clean, and a clear mountain stream is generally not safe to drink untreated. Ready.gov says to treat any water of uncertain quality before drinking, washing food, brushing teeth or making ice. Giardia symptoms usually appear one to two weeks later, so feeling fine proves nothing.

Your kidneys can only make urine less salty than seawater, so clearing the salt from a drink of it means passing more water than you drank. NOAA's summary: you dehydrate even as thirst grows. The Army survival manual puts seawater at about 4 percent salt and warns against even small amounts. Distilling it, by boiling and catching the condensed steam, removes the salt, and so can a solar still.

Neither belongs in place of water when you are working hard in heat. Ready.gov says not to drink caffeinated or carbonated drinks instead of water, and notes that caffeine and alcohol dehydrate the body, raising your need for water. Alcohol also impairs judgment and coordination. NWS likewise advises non-alcoholic, decaffeinated fluids in the heat.

Ready.gov advises keeping store-bought water sealed somewhere cool and dark, or using food-grade containers washed with soap and sanitized with a teaspoon of unscented bleach per quart, and replacing water you bottled yourself every six months. In freezing weather, store bottles upside down: water freezes from the top down, so the opening stays clear longest.

Water in your bottle does nothing until you drink it, while dehydration costs you now. Ready.gov's guidance is to drink what you need today and look for more tomorrow, rationing only if authorities order it. Save water by cutting what you lose, not what you drink: rest in shade, work in the cool hours and limit exertion. The Army survival manual's version: ration sweat, not water.

Early dehydration shows as thirst, dry mouth, less urine and sweat than usual, dark urine, tiredness and dizziness; the Forest Service adds headache and muscle cramps. Thirst is a late, unreliable signal, and some older adults barely feel it, so urine color is the better running check. Confusion, fainting, a racing heart or no urination means it is severe and needs medical help now.

Food can wait weeks but water cannot, and heat shrinks the margin: Grand Canyon rangers warn that heavy sweating on the trail can cost a quart or two every hour. That is why water outranks food in nearly every plan, with routes and rest stops built around where it can be found. The exceptions are threats that act faster still, such as serious bleeding, cold and wet exposure or a heat emergency.

Food and water are the heaviest things you carry, so the plan balances weight against need. Estimate need by time and heat, not just distance: hikers can sweat out one to two quarts an hour, and Death Valley advises at least a gallon a day. Know every reliable refill before you start, assume a listed spigot may be shut off, as Grand Canyon warns, and carry extra for delays.

Fire is one tool with many jobs: heat that spares the calories your body burns staying warm, drying wet clothes before they cause cold injury, boiling water, signaling with smoke by day and light by night, cooking, and the comfort of having one. Decide which job matters most before you build, since cooking, warming and signal fires are laid differently.

Pick flat, dry ground sheltered from wind and away from snow-laden trees, then scrape away leaves and duff to bare soil, about 3 feet across by the Army survival manual's minimum. Remove porous rocks, which can hold water and burst when heated. Keep your tent and gear at least 15 feet away and upwind, as NPS advises, and in deep snow build on a platform of green logs so the fire does not sink.

A match can light only fine material, and fine material burns out fast, so a fire is built in three steps that each feed the next size up: tinder, then kindling from pencil-lead to thumb thickness, then fuel at least as thick as your forearm. Skip a step and the fire usually dies. Gather all three before you strike, and lay kindling loosely so air reaches the flame instead of smothering it.

Tinder has to catch from a spark or a small flame, so it must be dry, fine and fluffy, with lots of surface and air around it. Thin fibers heat through almost at once, while a solid stick of the same wood will not. Gather more than you think you need, at least a cupped handful per fire by the Army survival manual's guide, and dry damp tinder between clothing layers where body heat works on it.

Good natural tinder is dead, dry and fine. The Army survival manual lists birch bark, dry grass, ferns, moss, lichen, fungi, seed down from cattail, milkweed or thistle, pine pitch and pitch wood shavings, and feather sticks cut from dry wood. Resin-rich pitch burns longer but may need fibers around it to catch. In rain, shave the dry inside of standing dead wood.

Carrying tinder removes the hardest part of lighting a fire in bad weather. The Army survival manual says cotton balls work best coated with petroleum jelly, and commercial pastes, wax-soaked cotton and solid fuel tabs work similarly: they catch from a spark and burn far longer than natural fibers. Keep them sealed and dry. NPS warns never to squirt lighter fluid onto embers or flames.

A lighter or match is the fastest ignition, and each fails differently. Matches soak up moisture, and every one that blows out is one fewer fire, so keep waterproof matches in a sealed container and shield the flame. Butane lighters resist wind and burn hotter, but extreme cold can stop lighter fuel working, so warm the lighter in your clothes. Carry a ferrocerium rod as backup.

A ferrocerium rod, which the Army survival manual calls a metal match, throws hot sparks from the same material as lighter flints, works wet or dry and hot or cold, and can start thousands of fires. The skill is the strike: drive a sharp 90-degree edge, such as the back of a knife, firmly down the rod toward the tinder. Hot sparks can offset a little damp, but not wet or coarse tinder.

A bow drill makes an ember by spinning a dry hardwood spindle in a notched softwood board until the dust smolders, then nursing that coal in a tinder nest. It needs seasoned wood, cordage, a socket, practice and a lot of energy, and resinous woods glaze over and fail. The Army survival manual notes that people who practice beforehand are much more likely to succeed. Learn it; do not plan on it.

Rain soaks the outside of wood, not the inside. Standing dead wood sheds most rain, while rotten wood on the ground mostly smolders, so gather from snags and dead low branches and split pieces to reach the dry inner wood. Build on a base of wood or nonporous stone off the wet ground, prepare extra tinder and kindling, and use a tepee lay, which the Army manual says burns well even with wet wood.

How you stack fuel decides what a fire does. A tepee of sticks leaned over the tinder feeds itself as the outer sticks burn and fall inward. A log cabin of crossed layers draws lots of air and quickly gives light, heat and a bed of coals, useful for cooking or a signal fire. A lean-to lay builds the fire under a green stick angled at about 30 degrees, and a pyramid burns downward overnight.

An open fire throws heat in every direction, so much of it is lost. A reflector wall of green logs or nonporous rock behind the fire sends heat back toward you and blocks wind, and at a shelter's opening it pushes warmth inside. The Army survival manual puts the best fire-to-shelter distance at about 3 feet, with the opening at 90 degrees to the prevailing wind to keep sparks out.

A survival fire must not become a second emergency. Never leave it unattended, keep water close and keep it small. Coals can hold heat for hours and flare in wind, so drown them and stir until everything is cold to the touch. Without water, spread the coals and keep stirring in dirt or sand, since dirt just piled on top can bank them hot. Check that the ground underneath is cool.

Smoke only signals if it stands out from what is behind it. Green leaves or other damp vegetation piled on a hot fire make thick white smoke; burning rubber, oil or other petroleum makes thick black smoke. Pick by background, using the FAA's contrast rule for ground signals: white against dark forest, black against snow. Stay out of petroleum smoke, which the Army manual warns is harmful.

A signal fire must be ready before an aircraft appears, since one may be in view only briefly. Build it in a clearing, on a hilltop or shoreline where smoke can rise free of tree cover, with tinder and fuel laid ready, and keep green vegetation close to pile on for thick smoke by day. At night, bright flame is the signal. The distress form is three fires in a triangle or line.

Once you have any signal, battery is your scarcest resource. Call 911 early with your location. If coverage is too weak for voice, try a text: one reached Denali rangers when calls could not, and rangers there have advised texting to save battery. Carry a spare battery, and after reporting your position, stay put, since rescuers can sometimes narrow your location from cell-site data.

Fire needs heat, fuel and oxygen at once, and removing any one puts it out, which is how you both start and stop one. A struggling fire has the balance wrong, so rearrange it, opening space for air or adding finer fuel, rather than piling on more. Do not confuse it with the fire behavior triangle of fuels, weather and topography, which NPS uses to explain how wildfire spreads.

In dry, windy conditions any open flame can start a wildfire that threatens you and everyone downwind. Check restrictions before you go; the Forest Service advises using alternatives to campfires in high fire danger even without a ban, and notes that nine in ten fires are human-caused. NPS's emergency plan says not to build a fire while awaiting rescue in high fire risk or fire season.

Any flame or engine burning in a closed space makes carbon monoxide, a gas you cannot see or smell, and a tent, snow cave or car cabin has little air to dilute it. Its symptoms, headache, dizziness, weakness, nausea, sleepiness and confusion, are easy to mistake for cold or fatigue. Keep stoves and generators outside, vent any heated shelter, and get to fresh air at once if symptoms appear.

Signals in sets of three stand out as deliberate, which is why three anchors distress practice: three whistle blasts, a break, then three more; three fires in a triangle or a line; and SOS by light or mirror, three short, three long, three short. Pause between sets to hear searchers answer, then repeat. Canada's AdventureSmart prevention program teaches the same pattern.

A mirror flash can reach aircraft and distant ridges over long distances and never runs out of battery, but it works only in sun and only where you aim it. Extend your free hand toward the target as a sight line and steer the reflected light along it. Practice on a nearby object first, and adjust as the sun moves. A knife blade, belt buckle or sunglasses can stand in.

Shouting burns energy you need, and your voice gives out; a whistle costs almost nothing to blow, so you can keep signaling as long as it takes. NPS suggests a whistle for each person, children especially, and blowing it often instead of yelling. Use sets of three with a pause, and stop now and then to listen, since ground searchers within hearing range can follow the sound to you.

Searchers spot what stands out from the landscape, so give them contrast and motion. Move into the open, such as a clearing, ridge or shore, rather than staying under trees, and stay there. Lay out bright clothing, a tarp or an emergency blanket, and wave, flash a light or blow a whistle when you hear searchers. Denali rangers asked lost hikers for exactly that.

Large ground symbols speak to pilots without a radio. The FAA's code uses V for needing help, X for needing medical help, N for no, Y for yes and an arrow for your direction of travel, with SOS if in doubt. Make symbols at least 10 feet high with strong contrast, using rocks, logs, fabric or trenches stamped in snow, which look black from the air. A pilot rocks the wings to acknowledge.

A personal locator beacon has one job: switched on by hand, it sends a 406 MHz distress signal by satellite to rescue authorities, with no subscription, and GPS-equipped models can place you within about 100 meters. It must be registered with NOAA and cannot send messages or cancel an alert. A satellite messenger needs a paid plan but adds two-way texting to explain or call off an SOS.

Each step taken after the map stops matching the ground carries you farther from the last place you were sure of, and the area searchers must cover grows with it. The earliest honest signal is a mismatch you catch yourself explaining away, such as a junction that never appeared or a stream on the wrong side. NPS guidance puts stopping to calm down first, then fixing your position, then retracing your steps only if that is safe.

Searchers begin at your last known position and work outward, so wandering can carry you outside the area they are covering or behind a team that has already cleared it. Once you have called for help, NPS guidance is to stay where you are and save energy, moving only if something threatens your life. Staying put also frees your effort for shelter and for signals that make you easier to spot.

The bar NPS sets for leaving your position is an immediate threat to life, not discomfort or a hunch that the trail is close. Rising water, fire, or exposure you cannot shelter from where you stand can meet that bar; boredom and impatience do not. If you relocate, keep the move short and purposeful, toward shelter, water or an opening aircraft can see, rather than a long hike toward rescue.

Retracing your route returns you to ground you have already crossed and can recognize, which is safer than pushing into unknown terrain hoping to reconnect. NPS lists it as a self-rescue step to take only if it is safe. It fails when you cannot remember the turns you made, so noting junctions and landmarks on the way in is what makes backtracking possible on the way out.

A mark serves two readers: you, if you need to retrace your steps, and searchers, who start from your last known position and need a line to follow from it. It only helps if it points the way you went and sits where someone will notice it, such as a junction or the spot where you left the trail. Marking is not a reason to keep walking; NPS guidance still favors staying put once you are lost.

A map is oriented when its north lines up with north on the ground, so a ridge to the left on paper is also to your left in front of you. You can orient it with a compass, correcting for declination, or by turning it until visible features line up. Deciding on an unoriented map invites a wrong turn at the first junction, and nearby steel such as a belt buckle or car can pull the needle off.

Instead of following a bearing blindly, you compare what the map says should come next with what you actually see: a saddle, a stream junction, a change in slope. Because you check constantly, an error shows up early and is easy to correct. Trust landforms over clearings and buildings, which may have changed since the map was printed, and expect heavy foliage to hide the shapes you are matching.

A handrail is a linear feature such as a stream, ridgeline, trail or power line that runs alongside your direction of travel, so you can follow it with only rough compass work. A catching feature is something prominent across your path near your turn or goal, like a road or river; reaching it tells you it is time to turn, or that you have gone too far.

When your goal sits on a road, stream or other linear feature, aiming straight at it leaves you unsure which way to turn if you hit the feature and the goal is not in sight. Steering deliberately to one side, often about 10 degrees, removes that doubt: you know to turn back toward the side you chose. Each degree shifts you about 18 meters per kilometer, so 10 degrees lands roughly 180 meters off.

Walk a measured course on terrain like the ground you will cross, count your paces, and work out how many it takes you to cover 100 meters. Track each 100 meters with a pebble or a knot rather than memory. The count drifts: climbing, sand, mud, snow, a headwind and poor visibility all shorten your stride, so the same distance takes more paces, while going downhill lengthens it.

The sun rises roughly in the east and sets roughly in the west, but rarely due east or due west, and the offset shifts with the seasons. Outside the tropics, the sun at its highest point marks due south in the Northern Hemisphere and due north in the Southern, with shadows swinging clockwise in the north. Within the tropics the noon sun can pass straight overhead, so treat the sun as a rough direction, not a bearing.

Push a straight stick upright into level ground and mark the tip of its shadow, then wait 10 to 15 minutes and mark the tip again. A line through the two marks runs roughly east-west, and the first mark is the west end anywhere on Earth, so standing with it on your left puts north in front of you. Marking the shadow in the morning and again at equal length in the afternoon gives a more accurate line.

The two stars forming the outer lip of the Big Dipper's bowl are the pointers: run a line through them and extend it about five times the gap between them to reach Polaris, the North Star. Cassiopeia, a sideways W opposite the Dipper, is a cross-check, since Polaris lies straight out from its middle star. Dropping a line from Polaris straight down to the horizon gives true north.

No bright star sits near the south celestial pole, so the Southern Cross, a tilted cross formed by four bright stars, serves as the pointer. Extend its long axis about five times its own length; where that imaginary line ends is roughly south, and dropping straight down to the horizon gives a landmark to steer by. Like the other star methods, it gives a general direction rather than a precise bearing.

Mosses depend on outside water to reproduce, so they thrive wherever bark stays damp, and slope, neighboring trees and nearby water can keep any side of a trunk wet. Some trees carry moss all the way around. That makes moss an unreliable compass even if it leans north in one stand of forest, so read direction from the sun, the stars or an actual compass instead.

A drainage is a ready-made handrail that leads toward lower, often easier ground, which is why the rule appeals once you have decided to move. In canyon country it breaks down: narrow drainages funnel flash floods, can twist into a maze of side channels, and can lead to rapids or waterfalls you cannot pass. Check the map for what lies downstream before you commit to following one.

Before you leave, study the route for places where you could cut the trip short by a known, easier way out: a side trail, a road crossing, a safer ford. Decide in advance what would send you there, such as a crossing running too high or weather building, and include those exits in the trip plan you leave with someone. Picking an exit on the spot, tired and rushed, is far harder.

Fog, blowing snow and darkness strip away the landmarks you steer by and shorten your stride, so bearings and pace counts drift faster than you notice. Any landmark you aim for has to be much closer, and every extra leg adds another chance for error. When you cannot see the next feature, slowing to a crawl or stopping until visibility returns is usually safer than pressing on.

A party that moves at its fastest member's pace strings out until someone falls behind unseen. NPS guidance is to match the pace to everyone in the group, check in often, agree on a meet-up spot that everyone can find on the map, and never let anyone split off alone; whoever turns back takes at least one other person. A photo of the group at the start records what everyone is wearing.

A GPS position depends on clear satellite signals. A phone is typically accurate to about 5 meters under open sky, but accuracy worsens near trees and buildings, and a dead battery ends navigation entirely. NPS advises learning to use a map and compass before you need them, carrying a physical map as a backup, and packing a spare battery for the phone or GPS unit.

A car is a large object that searchers can spot from a road or the air, while a person on foot in a storm is small and easy to miss. NWS warns that people who leave a stranded vehicle in wind-driven snow become disoriented quickly. Help rescuers by tying a bright cloth to the antenna or door and raising the hood once snow stops, and keep the exhaust pipe clear if you run the engine for heat.

Scale is the ratio of map distance to ground distance; on a 1:24,000 USGS map, one inch covers 2,000 feet. The larger the second number, the smaller the scale, so each inch spans more ground in less detail. Brown contours show elevation, blue marks water and green marks vegetation. The margin carries scale bars and the sheet's contour interval, while USGS explains its full set of symbols in a separate guide.

Each contour joins points of equal elevation, so contours never cross. Lines packed tightly together mean the ground rises steeply; widely spaced lines, or none, mean it is fairly level. Read the contour interval in the margin before judging a slope: it ranges from 10 feet or less on flat terrain to 100 feet or more in mountains, so the same spacing can mean very different steepness.

A bearing is an angle measured clockwise from north, 0 to 360 degrees, with east at 90, south at 180 and west at 270; the reverse direction differs by 180. An open compass held in front of you while walking will not read steadily, so sight along the bearing to a distinct landmark, walk to it, and repeat. Keep the compass away from steel such as knives, belt buckles and vehicles.

NOAA's sign convention keeps the arithmetic simple: east declination is positive, west is negative, and a true bearing equals the magnetic bearing plus the declination. With 10° west declination, a magnetic bearing of 45° is a true 35°. The value differs from place to place and drifts over time, so a printed map figure can be stale, and the needle follows the local field rather than pointing at the magnetic pole.

Hearing thunder at all means the storm is close enough to strike you, and bolts can land 10 to 15 miles from it, outside any rain. NWS advises moving at once to a substantial building with wiring or plumbing, or a hard-topped metal vehicle with the windows up, and staying there 30 minutes after the last thunder. Tents, open picnic shelters and dugouts do not count.

NWS is blunt that no outdoor spot is safe, so these steps only trim the risk when shelter is out of reach. Get off peaks, ridges and hilltops; stay out from under lone trees, the second leading cause of lightning casualties; leave the water; and keep clear of fences, power lines and other metal. Do not lie flat, which exposes you to ground current, and spread a group apart.

The human body does not store electricity, so a lightning victim is safe to touch and first aid can start immediately; hesitating over a false fear of shock is what costs lives. The storm may still be active, so move yourself and the victim to safety as soon as you can. Lightning kills about 20 people a year in the United States, and some survivors have lifelong neurological damage.

Decide whether to cross before deciding how. Rivers run colder, faster and deeper than they look, and levels rise after rain or on warm afternoons as snow melts upstream, so a morning ford can be dangerous by evening. Ask about conditions, plan a backup, and cross early. A stick tossed in upstream helps: if it floats past faster than you can walk, the spot is probably unsafe.

Unbuckle the hip belt and chest strap so a fall does not let your pack pin you face down or drag you under. Face upstream, lean slightly into the current and shuffle sideways at a slight downstream angle, moving one foot or pole at a time; a pole planted upstream gives a third point of contact. Keep footwear on, and avoid water above your knees unless it is a slow, flat pool.

On rugged coasts some headlands can be rounded only at lower tides, and reaching one late can leave you cut off on the wrong side of a point as the water rises. Olympic National Park advises carrying a tide table and a topographic map that marks those headlands, and keeping track of the time. Strong winds and storms can push tides above predicted levels, especially in fall, winter and spring.

Steep walls shed rock, and just after a fall the chance of more coming down is higher. Zion's guidance is to stay off closed trails, keep back from edges, and if rock falls from above, get behind the largest nearby boulder or move away from the wall. On snowy ridges a cornice can break farther back than it looks, and river bends often hide deep cut banks and swift water on the outside.

When blowing snow or fog erases the horizon, you lose the references that keep you on line, and each blind step compounds the error. An obscured edge can also hide an overhanging cornice you are already standing on. NWS advises drivers who cannot see to pull off and wait until visibility improves; on foot, stopping and sheltering where you are is likewise safer than guessing.

The danger in wild food lies less in the plant than in the identification. Poison hemlock has killed people who mistook it for wild carrot or parsnip, and toxin levels can differ between plants of the same species. Army survival guidance is to eat only plants you can identify with certainty, skip spoiling or moldy fruit, and never eat wild mushrooms in a survival situation.

The test has you try one plant part at a time and watch for a reaction, and each part takes more than 24 hours, so it is worth doing only for a plant that is abundant. Its blind spot is timing: a toxin whose symptoms show up days later passes, which is why Army guidance rules out mushrooms entirely. Positive identification remains the only reliable safeguard.

Heavy rain upstream can send a surge down a channel under a clear sky, because water that cannot soak into the ground rushes into streams and overtops them. Flash floods strike mountain streams, canyons, dry washes and low spots, sometimes arriving as a wall of water. Do not camp in a dry streambed, know your route to higher ground, and climb at the first sign of rising water.

CDC data cited by NWS show that more than half of flood drownings happen when someone drives into hazardous floodwater, and walking into or near it is the next largest share. People misjudge both depth and force, and the road beneath may already have collapsed. Never drive around barricades at a flooded road; turning back costs minutes, not a life.

Moving water pushes far harder than its depth suggests, and it lifts as well as pushes. NWS's Turn Around Don't Drown page says 6 inches of fast-moving water can knock over an adult, 12 inches can carry away most cars and 2 feet can carry away SUVs and trucks; its flood-safety page puts large vehicles at 18 inches. Murky water also hides its depth and whether the road beneath is still there.

A rip current is a narrow channel of water flowing away from the beach; it pulls you out, not under. Swimming straight back against it exhausts even strong swimmers, so swim along the shoreline until you are clear of the pull, then angle back to land. If you cannot break free, float or tread water and wave and yell for help. Permanent rips often run beside piers and jetties.

A dead or damaged tree can drop a limb or fall entirely without warning, especially in wind or under heavy snow, which is how widow-makers earn the name. The Forest Service advises against parking or camping where a tree could fall and lists warning signs: missing bark or needles, broken tops, fungal conks, many fallen limbs and heavy woodpecker damage. In strong wind, head for a clearing.

Black bears and brown or grizzly bears call for different responses once an attack happens, and the bear's motive matters as much as its species: a surprised mother defending cubs is not the same as a bear stalking you for food. Color is a poor guide, since black bears can be brown or cinnamon. NPS stresses that no single strategy fits every encounter and advises checking each park's current guidance.

If a black bear notices you and keeps approaching or following, change direction, then stand your ground and turn loud and aggressive: shout, bunch your group together to look bigger, and throw rocks or other non-food objects toward it. Never run or turn your back. If a black bear attacks, do not play dead; escape to a car or building or fight back, aiming at its face and muzzle.

With a grizzly, talk calmly so it knows you are human, back away slowly and give it room; a charge may be a bluff that turns away at the last second. If it makes contact in a defensive attack, keep your pack on, lie flat on your stomach with hands clasped behind your neck and legs spread, and stay still until it leaves. If the attack goes on, fight back hard.

Playing dead works against a bear that is defending itself, not one treating you as food. A bear that stalks you, approaches slowly but persistently, or attacks you in a tent is behaving like a predator, and NPS guidance for either species is to fight back with anything at hand. Yellowstone notes that predatory attacks usually go on until the bear is scared off, overpowered, injured or killed.

A bear that gets human food learns to seek out people, which endangers the next camper and often ends with the bear being killed. Yellowstone's rules: use food lockers or approved bear-resistant containers, or hang food and scented items at least 10 feet up and 4 feet from the trunk. Cook and store food at least 100 yards from where you sleep, and treat toothpaste, sunscreen and trash as food.

Bears, mountain lions and wolves tend to chase whatever flees, and a bear can outrun you uphill or down. Running also turns your back on the animal, so with predators, hold your ground or back away slowly while facing them. Large plant-eaters are the exception: NPS says it is fine to run from a moose, and Yellowstone advises walking or running away from a bison showing signs of a charge.

Bear spray is a deterrent aimed at the animal, not a repellent for skin or gear, and it leaves the can as a wide cloud, so aim matters less than with personal pepper spray. Carry it in a hip or chest holster, not your pack. If a bear charges, pull the safety, point slightly down, allow for crosswind and fire at 30 to 60 feet; a charging bear can cover up to 40 feet per second.

Attacks are rare, and if a mountain lion confronts you the goal is to look like a threat rather than prey. Stand upright facing it and hold eye contact; pick up small children without bending over, since a crouching person resembles four-legged prey. Raise your arms, open your jacket and speak loudly, throw objects if it advances, and if it attacks, fight back while staying on your feet.

In Alaska, moose injure more people each year than bears do, and in Yellowstone bison have injured more people than any other animal. These animals defend their space and young rather than hunt, and they seem calm enough that people get too close. Watch for laid-back ears, raised hackles, pawing or head bobbing, and get behind a tree or car, or move away fast.

Acute mountain sickness can hit even on an easy hike or a drive at elevations like Yellowstone's, mostly over a mile high: headache, nausea, dizziness, poor appetite, fatigue, a rapid pulse. The park's rule is to go no higher and descend, then wait at least a day at a comfortable elevation before climbing again. Poor balance, confusion, a wet cough or blue skin mean descend at once and get care.

The core habit is never putting a hand or foot where you cannot see. Stay out of tall grass and leaf piles where possible, do not climb on rocks or woodpiles, wear boots and long pants, and use leather gloves when clearing brush. Snakes are most active at dawn, at dusk and in warm weather, and a rattlesnake does not always rattle first and can strike a third or more of its body length.

Get to emergency care quickly, since antivenom works best started early, and do not drive yourself, because a bite can make you dizzy or faint. While waiting, sit or lie with the bite in a comfortable neutral position, take off rings and watches before swelling starts, wash and cover the bite, and mark the edge of the swelling with the time. Do not wait for symptoms.

CDC guidance rules out cutting the wound, sucking out venom, tourniquets, ice or soaking, electric shock and alcohol. Research it cites found that suction devices do not remove venom, cutting adds a second wound, and every one of these steps burns time that should go to reaching antivenom. A photo taken from a safe distance helps doctors identify the snake; trying to catch it only risks a second bite.

Disease carried by ticks and mosquitoes reaches far more people than snakebite does. More than 80,000 Lyme disease cases are reported to CDC each year, and an insurance-based estimate puts the number treated near 476,000, while about 7,000 to 8,000 people a year are bitten by venomous snakes in the United States. Treat clothing with permethrin, use an EPA-registered repellent and keep to the center of trails.

Remove an attached tick as soon as you find it rather than waiting to see a clinician, since delay raises the chance of infection. After time outdoors, including your own yard, check your whole body with a mirror, shower within two hours, and tumble dry clothes on high heat for 10 minutes. Check gear and pets too, and see a doctor if a rash or fever appears within several weeks.

After a disaster you may need to get by on your own for several days, which is the span Ready.gov plans for. The basics: water, nonperishable food, a battery or hand-crank radio, a flashlight, a first aid kit, extra batteries, a whistle, a dust mask, a wrench to shut off utilities, a manual can opener, local maps and a phone charger, packed in one or two easy-to-carry containers.

Ready.gov's planning figure is at least one gallon per person per day for several days, covering drinking and sanitation. An active adult needs about three-quarters of a gallon of fluid a day, and children, nursing mothers, sick people and hot weather push that higher; extreme heat can double it. Do not ration drinking water unless authorities say to, and replace water you bottled yourself every six months.

Pick canned goods, dry mixes and staples that need no refrigeration, cooking, water or special preparation, since power and gas may be out for days: ready-to-eat canned meat and vegetables, peanut butter, protein bars, dried fruit. Pack a manual can opener, choose foods your household will actually eat, and throw out any can that is swollen, dented or corroded.

A kit assembled once and forgotten slowly turns into expired food, dead batteries and medicine nobody can use. Keep canned food somewhere cool and dry and boxed food in tightly closed plastic or metal containers, replace items as they expire, and review the whole kit every year as your household's needs change. Check first aid supplies for expiration dates too.

After a disaster you may need to prove your identity and insurance coverage while power, ATMs and card readers are down. Ready.gov suggests copies of insurance policies, identification and bank records, kept in a waterproof portable container or saved electronically, plus a small amount of cash in small bills stored somewhere safe at home.

When phone systems are busy or down after a disaster, a text may get through where a call fails, and it uses less battery. Ready.gov's advice is to text unless you are in danger and save calls for emergencies, so you are not tying up lines that responders need. Official Wireless Emergency Alerts travel by a separate path that network congestion does not block.

Your household may be scattered when disaster strikes. Pick one contact outside your area for everyone to check in with, since it may be easier to reach someone out of town than across it. Agree on two meeting places, one in your neighborhood and one elsewhere in town in case you cannot get home. Keep written copies in wallets, cars and kits, and review the plan every year.

Rehearsal is where the gaps show: a child who cannot find the meeting place, a contact number nobody saved, a water valve rusted open. Walk the evacuation routes, run an earthquake drill, and have everyone locate the gas shutoff without actually closing it, since only a qualified professional should turn it back on. NPS gives the same advice for trips: practice the plan before you leave.

Know where you would go, and choose destinations in different directions in case the hazard blocks one way out. Learn primary and alternate routes, keep a go-bag where everyone knows to find it, and keep at least half a tank of gas, because stations may close or lose power. Leave early, follow official routes rather than shortcuts, and note that most public shelters accept only service animals.

Staying inside is safer when the outside air is the danger, such as a chemical release or heavy debris in the air, or when authorities order it. Bring everyone in, lock doors, close windows, vents and fireplace dampers, turn off fans and forced-air systems, and move to an interior room with few windows. Plastic sheeting and duct tape cut in advance let you seal it quickly.

Learn the shutoffs before an emergency. Gas procedures differ by meter, so ask your gas company, and remember that only a professional can restore gas once it is off. Find and tag the main water valve and make sure it closes fully; closing it keeps contaminated water out and holds clean water in your pipes and tanks. For electricity, switch off individual circuits before the main breaker.

If you smell gas or hear a hiss, getting everyone out comes first. Ready.gov advises opening a window on the way, closing the outside main valve if you can, and calling the gas company from a neighbor's home. Avoid anything that could spark, such as light switches and appliances, because an electrical spark can ignite leaking gas, and never turn the gas back on yourself.

The tank on your tap water heater holds clean water that CDC lists as an emergency drinking source, along with clear, untreated toilet tank water (never the bowl) and melted ice. Use the heater that feeds your faucets, not a tank that supplies radiator heat. Shutting the main water valve keeps that water from draining away and keeps contaminated water from entering your pipes.

Carbon monoxide has no color or smell, and a generator in an enclosed space can build deadly levels within minutes that linger for hours. Run generators, camp stoves and charcoal grills only outdoors and at least 20 feet from windows, doors and vents, never in a garage even with the door open, and never heat a home with a gas oven. Put battery-backed CO alarms on every level.

Never plug a generator into a wall outlet to power the house wiring; this backfeeding can electrocute utility workers and neighbors on the same transformer, and it bypasses household circuit protection. Run appliances from heavy-duty outdoor extension cords instead. Keep the unit dry, since a wet generator can shock you, and shut it off and let it cool before refueling, because fuel spilled on a hot engine can ignite.

Keep the doors shut: an unopened refrigerator holds food cold for about four hours and a full freezer for about 48. Use a thermometer, and discard perishable food that has sat at 40°F or warmer for two hours or more, or that smells, looks or feels wrong. Thawed food that still holds ice crystals can be refrozen. When in doubt, throw it out.

When shaking starts, drop to your hands and knees, cover your head and neck with an arm, crawl under a sturdy table if one is close, and hold on until it stops. If you are indoors, stay there: Ready.gov says not to run outside and to stay out of doorways. In bed, turn face down and cover your head with a pillow; outdoors, move clear of buildings, trees, streetlights and power lines.

Expect aftershocks and be ready to drop, cover and hold on again. If the building is damaged, get out and away from it and do not go back in; leaking gas, broken water lines and downed power lines are common. If trapped, text, bang on a pipe or wall, or blow a whistle instead of shouting, and cover your mouth. Near a coast, head inland or to higher ground once shaking stops.

Flying debris can kill, so put as many walls and floors as possible between you and the outside. Best is a safe room or certified storm shelter; next best is a small, interior, windowless room or basement on the lowest floor of a sturdy building. Cover your head and neck with your arms and shield yourself with blankets or furniture. A highway overpass is a poor shelter.

If you live in an evacuation zone and officials order you out, leave immediately, so learn the routes and where you would stay ahead of time. Before the storm, clear drains and gutters, bring in outdoor furniture, consider shutters, charge phones and stock supplies, since stores may be closed for days or weeks. If rising water traps you, go to the highest floor, but not into a closed attic.

Storm surge, seawater driven ashore by a storm's winds, is the leading cause of hurricane deaths in the United States. It can push up rivers and canals well inland, and when it arrives with high tide the water can rise 20 feet or more. A storm's size, speed, angle and the shape of the coast also shape the surge, so wind category alone does not predict it and evacuation orders follow surge zones.

Wildfires spread quickly, so leave as soon as authorities tell you to, or sooner, rather than staying behind to protect the house. People who wait risk being trapped, and Ready.gov warns that if you are trapped and call for help, emergency response may be delayed or impossible. Keep the go-bag packed and know your routes before fire season starts.

Clearing what can burn near a house gives a fire less to carry to it. Ready.gov advises keeping a zone at least 30 feet out from the home free of leaves, debris and other flammable material, building or repairing with fire-resistant materials, and having a hose that reaches every part of the property. Do the work before fire season; once smoke is visible there is no time left.

Flood cover comes from a separate policy, such as one through FEMA's National Flood Insurance Program, and Ready.gov says a new policy typically takes up to 30 days to take effect, so buying one as a storm approaches is too late. Flood maps help you judge risk, but flooding does not follow the lines on a map, and floods are the most common disaster in the United States.

A watch means conditions make a hazard possible but its timing or location is still uncertain, so set your plan in motion and keep listening. A warning means the hazard is happening, imminent or likely, and people in its path need to act now. Have more than one way to receive alerts, such as Wireless Emergency Alerts, NOAA Weather Radio and the FEMA app.

Rank problems by how fast they can kill. A person can bleed to death within minutes, so life-threatening bleeding gets controlled first, then the airway is opened and breathing checked, and only then do lesser wounds, burns and splints get attention. The exception is a conscious person who is choking, whose airway comes first. Send for help as early as you can alongside all of it.

Press firmly on the wound with gauze, a shirt or your bare hand, on a firm surface if you can, and pack a deep, gaping wound before pressing. Stop the Bleed advises holding at least 5 minutes before you look, and the Army survival manual says not to remove a dressing even when it soaks through. For life-threatening bleeding on an arm or leg, Army first aid and Stop the Bleed put on a tourniquet first.

For life-threatening bleeding from an arm or leg, Army first aid applies a tourniquet at once rather than as a last resort. The Army survival manual places it 2 to 3 inches above the wound and tightens it until the bleeding stops, and Stop the Bleed adds a second one above the first if needed. Mark the time it went on and leave it in place for responders; Stop the Bleed says not to loosen it.

Pulling out an object stuck in the body can cause more bleeding and further nerve or muscle damage. Leave it in, keep the person still, and build bulky padding around it so it cannot shift, then tape the padding in place without pressing on the object. Army guidance allows removal only when the object is blocking the airway or passes through the cheek with both ends visible.

Because a bowline's loop stays the same size under load, it will not tighten around a person, post or ring, and it stays easy to untie once the load comes off. Two cautions: it cannot be untied while loaded, and it can shake loose when left slack, which is why climbers back it up with an overhand knot tied in the tail.

The taut-line hitch wraps around the line's own standing part and holds by friction, so you can slide it along to tighten a tent guyline and it grips once loaded. How well it grips depends on the cord: twisted nylon can let it creep over time, which an extra turn or half hitch may stop, and in polypropylene or Dyneema expect it to slip outright.

A square knot draws tighter under a steady, even pull, which is why Army survival and mountaineering manuals list it for joining two ropes of equal diameter, the mountaineering manual only with an overhand knot securing each side. Under an uneven or shifting pull it can capsize and slip apart, so knot references say never to trust it with a critical load; a double fisherman's or figure-eight bend is the safer join.

A trucker's hitch forms a loop partway along the line, then runs the free end around an anchor and back through that loop, which works like a pulley. In theory that gives a 3:1 advantage, though rope rubbing on rope cuts the real gain to perhaps 1.6:1. The same friction helps hold the tension while you pinch the line and finish with two half hitches.

Shock means the organs are not getting enough blood flow, often after heavy bleeding, and it can worsen fast. Look for pale, cool, clammy skin, a rapid but weak pulse, fast breathing, restlessness or confusion, and thirst. Heat exhaustion can look much the same, so the situation matters, while heat stroke brings hot skin and a strong pulse. Call for help, lay the person flat and keep them warm.

A broken bone shifts whenever the joint at either end moves, so a splint that stops short lets the broken ends keep grinding. Extend padded rigid supports past the joints above and below the break and tie them above and below it, never over it. Do not force a deformed limb straight; Army first aid leaves straightening a broken thigh to medical personnel. Check below the break often for numbness, coolness or pallor.

Army first aid treats anyone with a head or neck injury as possibly having a spinal injury too, and a damaged spine moved carelessly can injure the cord and paralyze everything below that level. Do not move a person with a suspected neck or back injury unless staying put endangers life, as near a fire. If you must, move them as one unit, keeping the head and neck in line with the torso.

Once bleeding stops, CDC advises checking the wound for dirt and debris, gently flooding it with bottled or clean running water, saline if you have it, then cleaning around it with soap and water. Soil and sand carry bacteria into a wound, so never pack one with them. Leave dirty wounds, bites and punctures open rather than closing them, since a wound that was not cleaned well can trap bacteria.

Infection tends to show in the days after an injury: pain that grows instead of fading, spreading redness, warmth, swelling, pus or other drainage, or fever. Any of these means the wound needs medical care, not more waiting. Bites, dirty punctures, crush injuries and embedded debris raise the risk, and CDC's tetanus guidance calls for a booster after a dirty wound if the last dose was 5 or more years ago.

Cool a burn under cool running water, at least 5 minutes by the American Burn Association and 20 where possible by the Army survival manual, which uses only brief cool compresses on a deep burn. Ice deepens the damage, and butter, oil or ointment trap heat. Leave blisters intact and cover loosely. A full-thickness burn can be painless, and burns larger than a hand or on the face, hands, feet or genitals need care.

The skin over a friction blister keeps the raw layer underneath clean while it heals, so leave it in place. Cut padding into a ring, set it around the blister to take the pressure off, and cover both loosely with a bandage. If a blister is large and very painful, dermatologists allow draining it from one edge with a sterilized needle, keeping the roof on and watching for redness, pus or swelling.

Grip the tick with fine-tipped tweezers as close to the skin as possible and pull away with steady, even pressure; twisting or jerking can leave the mouthparts behind. Skip petroleum jelly, nail polish, heat and other tricks, which agitate the tick and can force infected fluid into the skin. Clean the bite and your hands afterward, and never crush the tick with your fingers.

Rinse with seawater to wash off venom and lift away tentacle pieces with tweezers or double-gloved fingers, never bare hands. Do not use fresh water, which can set off stinging cells still on the skin. Vinegar depends on the species: it stops box jellyfish stingers from firing but can release more venom from a Portuguese man-of-war and some other jellyfish, so follow local guidance.