Guide · Self-sufficiency

Heating without electricity, without CO risk

Keep the heat in first, get equipped second, and one absolute rule: never combustion without ventilation.

Updated September 16, 2026Reading: 6 minOfficial sources cited at the bottom of the page
In brief

Before looking for a portable heater, start by keeping the heat already present: close shutters, insulate windows, gather in a single room. If you use a gas or oil portable heater, do it intermittently (about 2 hours), in a ventilated room, never continuously or while sleeping. A generator never runs indoors: it's the leading cause of death by accidental poisoning in the home in France.

The hierarchy that works

  1. Keep the heat already there

    The safest and cheapest solution: limit losses before trying to produce heat.

  2. Gather in a single room

    Smaller to heat, easier to insulate, and simpler to monitor.

  3. Get a safe portable heater, as a last resort

    Always with ventilation, never continuously, never for the night.

Keeping the heat before heating

Getting a portable heater, safely

If a gas or oil heater becomes necessary, health authorities (prefectures, ARS) give precise rules:

RuleWhy
Occasional use, about 2 hoursProlonged or continuous use greatly increases the poisoning risk.
Properly ventilated roomIncomplete combustion, due to lack of air, releases carbon monoxide.
Never while sleepingEarly poisoning signs (drowsiness, headaches) go unnoticed during sleep.
Carbon monoxide detector as a complementIn addition to the smoke detector, already mandatory in every home.

Carbon monoxide: the one real ban

Carbon monoxide (CO) is an odourless, colourless, non-irritating gas: it can't be smelled, seen, or felt stinging the eyes. That's what makes it dangerous. According to the Ministry of Health, it is in France the leading cause of death by accidental poisoning in the home, with around 3,000 people poisoned every year.

What must never be done: using a generator or a barbecue indoors, blocking a home's air inlets and outlets (even in extreme cold), or leaving a combustion heater running all night in a closed room.

Authorities recommend airing for at least 10 minutes every day, even in the depths of winter, and keeping ventilation systems in good working order.

Mistakes to avoid

With LASTLINE

Practical guides, even without network

LASTLINE doesn't replace a carbon monoxide detector, but can help you:

LASTLINE doesn't detect carbon monoxide: only a dedicated physical detector can.

See my practical guides

Frequently asked questions

Can a gas or oil portable heater be used continuously?

No. Health authorities recommend occasional use, limited to about 2 hours, and reserved for properly ventilated rooms. These devices must never run continuously, nor in a closed room without ventilation.

Should all air vents be closed to keep the heat in?

No, never completely. Health authorities remind us that air inlets and outlets must never be blocked, even in extreme cold, and that a room should be aired for at least 10 minutes a day, even in winter.

What are the signs of carbon monoxide poisoning?

Headaches, nausea, dizziness and unusual fatigue affecting several household members at the same time should raise the alarm. Since carbon monoxide is odourless and colourless, these symptoms are often the only warning sign. If in doubt, go outside for fresh air and call 15 or 112.

Sources

  1. Nord Prefecture, Carbon monoxide and portable heaters: the right actions.
  2. Ministry of Health, Carbon monoxide poisoning.

In case of unexplained illness affecting several people at once, go outside immediately for fresh air and call 15 or 112.