A British winter with no heating is the scenario this whole app is built around, and hypothermia is its most likely medical consequence. It does not need arctic conditions. Most UK hypothermia happens indoors, in unheated houses, to older people, over days rather than hours.
The treatment is mostly obvious. One part of it is the opposite of what instinct says, and that part kills people.
Why this matters more than it used to
In an ordinary winter the house is heated and this is a rare problem. In the scenario here, several things stack:
- No central heating, and a single warm room at best.
- People sitting still, because there is less to do and less light.
- Reduced food intake, and shivering burns a great deal of energy.
- Wet clothing from fetching water, wood or working outdoors, with no tumble dryer.
- Older household members, who feel cold less accurately and generate less heat.
- Alcohol, which feels warming and is not.
It comes on slowly and the person does not notice. Impaired judgement is an early symptom, so the affected person is the least able to recognise it. Someone else has to.
Recognising the stages
Afterdrop, and why rubbing kills
Mild hypothermia
Shivering, conscious, talking sensibly, able to look after themselves. Active rewarming is appropriate here and by a non-medical person.
- Get them out of the cold, indoors, out of the wind.
- Remove wet clothing and replace with dry. Wet clothing conducts heat away many times faster than dry.
- Insulate them, including underneath. The floor takes more heat than the air does. Blankets, sleeping bag, duvet, and something under them.
- Cover the head.
- Warmth to the torso. A wrapped hot water bottle on the chest, warm packs in the armpits and groin, or another person's body heat under shared covers.
- Warm sweet drinks, if they are fully alert and can swallow safely. The sugar matters as much as the warmth, because shivering burns through reserves.
- Food, for the same reason.
- Let them shiver. It is doing useful work.
- Keep them still and horizontal-ish while they recover.
Moderate to severe
Nobody is dead until warm and dead
Preventing it
Far easier than treating it, and this is the part that belongs in an ordinary winter evening rather than an emergency.
- Heat the person, not the house. Layers, hats indoors, blankets, hot water bottles. A house is expensive to warm and a person is not.
- One warm room, everyone in it, door shut, window covered, draughts blocked. The scenario cards already say this and it is the single most effective measure.
- Get off the floor. Cushions, a duvet, a folded blanket. Conductive loss downward is larger than most people expect.
- Stay dry. Change out of damp clothing immediately, and treat drying clothes as a daily priority when there is no dryer.
- Eat and drink. Staying warm is metabolically expensive. Hot meals, and something before bed.
- Move regularly, without sweating.
- Sleep close together. Shared body heat under one set of covers beats separate beds by a wide margin.
- Check on people. Older relatives and neighbours, and anyone alone, daily. Hypothermia indoors develops over days and the person will not report it.