Portable heaters: how to use them safely

Warm and safe: a few habits are enough.

The answer in 2 lines. A portable heater can help, but it should not replace your main heating. Electric heaters go straight into a wall socket, never an extension lead, and are never covered or used to dry clothes. Gas and paraffin heaters burn fuel and give off carbon monoxide: use them only in a well-ventilated room, never while you sleep, and have a CO alarm. Keep any heater well away from curtains, furniture and bedding, and switch it off when you go out or to bed.

The first 3 steps

Keep the heater well away from curtains, furniture, beds and clothes, on a flat, stable surface.
Plug an electric heater straight into a wall socket, never an extension lead or adaptor.
Ventilate the room when a gas or paraffin heater is on, and switch it off before you sleep.

Stop: danger

A gas or paraffin heater left on for hours with the windows shut: risk of carbon monoxide poisoning.
An electric heater used to dry clothes or covered with anything.
A heater on an extension lead: it can overheat and catch fire.
A generator, barbecue or patio heater used indoors: deadly carbon monoxide.

Gas and paraffin: short periods, good ventilation

These heaters burn fuel and release carbon monoxide and moisture into the room.

Do not block vents or air bricks.
Never use them in a bedroom at night.
Fit an audible carbon monoxide alarm in the room.
Have a portable gas heater serviced by a Gas Safe registered engineer, and change cylinders outdoors, away from flames.
Paraffin: use only the right fuel, refuel outdoors with the heater cold.

Electric: watch for overheating

Never put anything on it: no clothes, no blankets.
Keep it away from curtains and furniture.
Plug it straight into a wall socket. A heater can draw most of what a 13 A socket can safely take.
Switch it off and unplug it when you go out or to bed, unless it is designed to be left on and has a thermostat and timer.
Buy from a reputable seller and register it with the maker so you hear about recalls. Electrical Safety First lists product recalls.

What not to do

A plug or socket that gets hot: stop using it (see our guide on a hot socket).
Heaters with a damaged cable, or cheap heaters from unknown online sellers.
Using a gas oven or hob to heat the room.

Good to know

Signs of carbon monoxide: headache, dizziness, nausea, tiredness, several people unwell at once. Get outside, call 999 if anyone is unwell, or 0800 111 999 for a suspected leak.
Older people living alone and people with limited mobility are at higher risk: check on neighbours in cold weather.
Many fire and rescue services offer free home fire safety visits.

If you rent

If you use a heater because your main heating has broken down, tell your landlord in writing straight away: in England, landlords must keep the installations for space heating and hot water in repair. Ask them about a replacement heater while it is fixed.

The figures

We could not confirm recent official figures on fires caused by portable heaters for this guide, so we do not quote any.

During a cold snap in Sheffield, the boiler in Marta's rented flat breaks down. She tells her letting agent by email and uses an electric heater, plugged straight into the wall, a metre away from the sofa. She switches it off before going to bed. The boiler is repaired two days later.

A made-up story, for illustration.

Bobby

Sources, verification, confidence

Verified on 18 October 2026, for England. Confidence: high for the safety rules and CO risks; medium for the distance from furniture, which depends on each model (follow its manual). No heater fire statistics are quoted. This guide describes common cases, not a diagnosis.