Learn what to do in the minutes before help arrives — the lay-rescuer knowledge behind CPR, AED, and first-aid courses, taught from current consensus guidelines (2025 AHA/ARC). Master the cardiac chain: recognizing cardiac arrest (unresponsive, not breathing normally — agonal gasps count as not breathing), high-quality compressions (100–120 per minute, 2–2.4 inches for adults, full recoil), rescue breaths and hands-only CPR, AED use and pad placement, and the differences for children and infants. Then the wider first-aid core: choking for adults, children, and infants; severe-bleeding control the Stop the Bleed way (direct pressure, wound packing, tourniquets); stroke recognition with FAST; heart attack vs cardiac arrest; anaphylaxis and epinephrine auto-injectors; the opioid-associated emergency and naloxone; seizures, diabetic emergencies, burns, fractures, heat stroke vs heat exhaustion, hypothermia; the recovery position; scene safety, consent, and Good Samaritan basics; and water-safety rescue priorities (reach–throw–row–go). Every explanation names the dangerous myth (the blind finger sweep, butter on a burn, leaning a nosebleed back) and leaves a rule you keep under stress. Educational practice only — it does not certify you and is not medical advice; take an in-person course to be certified, and in a real emergency call 911 and follow dispatcher instructions.