Power & Energy Autonomy
Staying Warm (and Cool) When the Power Is Out
When the grid fails in winter or a heatwave, temperature — not light — is the first threat to health. Practical, low-tech ways to keep a safe core temperature without electricity.
In a blackout, most people worry about phones and lights first. The real danger is temperature. A home that loses heat in a cold snap, or stays sealed and oven-hot in a heatwave, becomes unsafe within hours — long before the food in the fridge spoils. This guide is about the cheapest, most reliable ways to hold a safe body temperature when the grid is down.
The principle: one room, one shell
You do not need to heat or cool the whole house. Pick one small room, close it off, and treat it like a tent: a small volume is far easier to keep comfortable than a whole building. A bedroom with the door shut, curtains drawn and a towel along the bottom of the door can stay 5–10°C warmer than the rest of the home with no energy at all.
Warm people, not spaces
Cold: layer, seal, store heat
- Layer — several thin layers trap air better than one thick one. Cover the head, hands and feet; you lose most heat from the extremities.
- Seal — block draughts at doors, windows and chimneys you are not using. Still air is insulation. Bubble wrap taped to a window pane is a genuine, if ugly, upgrade.
- Store heat — fill bottles with hot water (from a gas stove or kettle) and put them in the bed or at your feet. A hot meal is both calories and a radiator.
- Move — light activity keeps circulation up. Avoid sweating (wet clothes cool you fast) but do not sit still and shiver for hours.
Heat you can make without the grid
- Safe indoor options: a capped tea-light in a terracotta pot (flowerpot heater) warms a small area and uses almost no fuel — but only in a ventilated space, never overnight unattended.
- A gas camping stove or butane burner boils water and cooks, which doubles as heating. Use only where there is airflow; carbon monoxide is the silent killer.
- Warmth from your stored power: a small fan or a low-watt heater on a power station keeps one room livable — see the energy-autonomy section for sizing.
Never burn these indoors
Heat: cool without AC
In a heatwave the goal is the opposite — stop heat getting in and move it out. Shade windows from late morning, close the south- and west-facing ones by day and open everything at night when it is cooler. Cross-ventilation (a window open at each end) beats a fan pointing at a wall. Damp a sheet and hang it in a breeze; evaporation does the work an AC would.
- Drink, and let others drink — dehydration creeps up when you cannot feel sweat. Babies, older relatives and pets are the first at risk.
- Cool the body, not the room: a wet cloth on neck and wrists, cool (not ice) footbaths, and a battery fan directed at a person drop core temperature fast.
- If you have stored power, run a fan off the station during the worst hours rather than a fridge you can manage by opening rarely.
What to keep on hand
| Need | No-power option |
|---|---|
| Warmth | Duets, blankets, thermal layers, hot-water bottles, hand warmers |
| Cooking / hot water | Gas camping stove + fuel, matches, kettle |
| Light + a little heat | LED lantern; a station running a low-watt fan |
| Cooling | Battery fan, damp sheets, shaded windows, water store |
| Power to stretch it | Power station + folding solar panel (recharge the fan) |
Tie it to your energy plan
The takeaway
Key idea
Temperature is the first health risk in an outage, and the cheapest to beat: one sealed room, layered people, stored heat (or shaded, vented cooling), and never a flame without air. Add a little stored power and a blackout becomes uncomfortable, not dangerous.
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