Nothing burns like the cold. Follow these instructions and you'll survive.
ACT
Cut off the cold. Now.
- Get out of the wind. Wind cancels any insulation. A hollow, a tree trunk, a wall: anything that blocks it beats a perfect Building an emergency shelter ten minutes' walk away.
- Take off everything that's wet. Damp clothing drains your heat faster than open air. Cut it off if the person is stiff.
- Insulate from the ground. Branches, cardboard, bags, foam, dead vegetation. The ground pulls heat out of you as much as the air does, and nobody thinks of it.
- Wrap them up. Head and neck included. Emergency blanket with the silver side facing in, with an insulating layer between the film and the body.
- Warm the torso. Never the limbs. Chest, armpits, groin. The arms and legs can wait.
- Sugar and a hot drink if, and only if, the person is fully conscious and swallows without difficulty. To heat the drink, see Making and keeping a fire.
Handle them with extreme gentleness. No sudden movement, no standing them up, no shaking. A chilled heart can stop from one careless movement. Everything is done lying flat and slowly.
Never give alcohol. It makes you feel warm and kills you faster.
If there's a bleeding wound, it comes before the cold: see Severe external bleeding.
ADAPT
You're alone. You can only count on your own shivering. Move to keep it going, eat what you have, and get to shelter before you're exhausted, not after. Someone alone at stage II can no longer save themselves: that's the line not to cross.
There are two of you. Direct body contact, chest to chest under shared insulation, works. The one who is fine stays dressed and dry: two hypothermic people don't warm each other up, they cool down together.
In a group. One person decides and gives the orders. The others carry them out — on how to hold a group together, see Trading, negotiating, keeping your word. Hypothermia managed by committee loses the minutes that count.
In a city. Stairwells, underground parking garages, utility rooms: out of the wind and above freezing. The same places also hold water reserves, see Making water safe to drink. The floor there is concrete: always insulate yourself from it.
With no gear. Cardboard is an excellent insulator. Plastic bags filled with dead leaves or crumpled paper, pulled on around the torso and legs, do the job. What counts is never how good it looks, it's the still air trapped inside.
For prevention, three levers, in this order: stay dry, block the wind, eat. A thin windbreaker on top beats one thick layer on its own. And know this: wet cotton is the worst material humanity ever produced against the cold.
UNDERSTAND
Cold needs neither snow nor frost. Water, wind and a few hours are enough. Water conducts heat about twenty-five times faster than air: falling into water changes the timescale completely.
The body fights as long as it can. It shuts down the periphery to protect the core, speeds up the heart, shivers. Shivering is the best heating it has: muscle working without producing movement, which means pure heat.
When the shivering stops, it doesn't mean things are getting better. It means the reserve is empty.
It's the only sign that really counts, and it's worth every thermometer:
| Stage | What you see | Temperature |
|---|---|---|
| I — mild | Conscious, intense shivering, cold skin | 32–35 °C (90–95 °F) |
| II — moderate | Drowsy, shivering has stopped, confused speech | 28–32 °C (82–90 °F) |
| III — severe | Unconscious, pulse barely detectable | 24–28 °C (75–82 °F) |
| IV — profound | No apparent sign of life | below 24 °C (75 °F) |
Why you never warm the limbs first: the blood pooled in the arms and legs is colder than the blood in the core. Sending it back to the heart all at once drops the core temperature at the very moment you thought you were saving the person. It's a trap that has killed people who were doing everything right.
Why extreme gentleness: a chilled heart muscle becomes electrically unstable. A jolt, standing up, a bump can trigger fibrillation. The move that saves a life looks like pointless slowness. It isn't.
There's one more trap. At advanced stages, the person may feel a flush of heat and start undressing: that's terminal vasodilationThe blood vessels in the skin opening up, which feels like warmth while speeding up heat loss., the body losing control of its blood vessels. A person undressed in the cold is an absolute emergency, not someone who's warm.
And there's a rule mountain rescuers repeat because it saves lives: nobody is dead from cold until they're warm and still dead. A deeply chilled body imitates death — stiff, fixed pupils, no pulse you can find — because the cold has put the metabolism on standby instead of switching it off. Long resuscitations have brought people back from there. Never declare someone dead in the field.