Hypothermia. Shivering that stops is a bad sign, not a good one. Confusion, clumsiness, slurred speech, apathy, and eventually undressing because the person feels hot. Cold skin, slow breathing, slow pulse.
- Handle them gently. Rough movement of a very cold person can trigger a fatal heart rhythm. No shaking, no dragging, no vigorous rubbing.
- Out of the wind and wet. Remove wet clothing by cutting it off rather than manoeuvring them, and dry them.
- Insulate everything, including from the ground, which takes heat faster than the air. Blankets, a bivouac bag, dry clothing, head covered.
- Warm drinks only if they are fully alert and can hold the cup. No alcohol — it feels warming and increases heat loss.
- Call the emergency number for anybody confused, drowsy, or not improving.
- If they are not breathing normally, start compressions and keep going. Cold profoundly slows the body, and people have recovered from hypothermic arrest after long resuscitations.
Frostbite. White, waxy, hard, numb skin — usually fingers, toes, nose, ears, cheeks.
- Get them somewhere warm and remove rings and tight clothing before swelling starts.
- Do not rub the area, do not apply direct heat, and do not use snow.
- Do not thaw it if there is any chance of it freezing again. A part thawed and refrozen is far worse than one that stayed frozen until proper care.
- Rewarm in warm — not hot — water where medical care is hours away, then protect it loosely and get help. It will hurt badly as it thaws.
Source. European Resuscitation Council, Guidelines 2021, First Aid and special circumstances, https://cprguidelines.eu/guidelines-2021 ; World Health Organization, https://www.who.int/emergencies
What this is not. Reading, not certification.