Is it okay to leave a space heater on all night?

Author: Prof. Beth Daugherty MD  |  Last update: Wednesday, February 11, 2026

Never leave your space heater alone in the room The best way to prevent a fire is to never leave a space heater running in a room unattended—that way, if anything does go wrong, you can take action quickly.

Is it OK to sleep with a space heater on?

If a space heater falls over or becomes too hot from running for too long of a period of time, that can lead to a fast-moving fire that occurs while you are asleep and cannot act fast enough. We do not recommend using space heaters at all because of this risk, but you definitely should not use them at night.

Can space heaters be left on overnight?

Running a space heater overnight increases the risk of fire. If the unit is left unattended or placed too close to flammable materials, such as curtains or bedding, it can ignite and lead to a devastating fire.

What happens if you forget to turn off the space heater?

Always turn off the heater when you leave the room. Extended use of heaters can make them break down internally, and they could catch fire. Plus, you waste energy when the space heater is keeping an empty room warm. To be on the safe side, look for a space heater that has automatic shutoff features.

How long can a space heater run continuously?

The duration for which you can leave a space heater running depends on the time of day and your specific needs. During the Day: It's safe to leave your heater on for 6-8 hours if you're in the room. If you're busy or moving between rooms, consider using a timer to automatically shut it off after a few hours.

Is it safe to leave a space heater on overnight?

Can you overuse a space heater?

Overusing the heater or using an oversized heater can result in elevated levels of carbon monoxide or nitrogen dioxide fumes in the air. These fumes can cause cold or flu-like symptoms, headaches, and eye, nose and throat irritation.

How likely is a space heater to start a fire?

According to the Consumer Product Safety Commission, space heaters are involved in more than a thousand home fires every year.

What is the number 1 cause of house fires?

Cooking. Unattended cooking is listed as the number one cause of residential fires.

Is leaving a space heater plugged in a fire hazard?

While electric space heaters can help keep room temperatures warm, they can also be dangerous and cause fires. Space heaters should never be left unattended or used within three feet of any combustibles and should always be plugged directly into an outlet.

How safe are space heaters?

But they can also pose a safety risk no matter where you use them. Portable space heaters were involved in an average of 1,700 house fires a year from 2017 to 2019, according to the most recent statistics from the Consumer Product Safety Commission. These fires resulted in an average of 70 deaths annually.

How close can a space heater be to your bed?

Most home heating deaths happened because a space heater was too close to furniture, clothing, mattresses, or bedding. Make sure your heater is at least three feet from anything that can burn.

Do space heaters shut off automatically?

Space heaters must have an automatic safety switch (tip-over switch) that turns the unit off if it is tipped over. Space heaters must have a thermostatic control which ensures that the unit will turn itself off and pre vent overheating or creating an electrical hazard.

Can I leave my electric heater on all night?

It is not safe to run a space heater overnight. If you use an electric or propane space heater during the day, make sure to protect yourself and your home by following all safety practices. Use space heaters that automatically turn off if they tip over. Only plug space heaters into grounded outlets.

Is it cheaper to turn up the heat or use a space heater?

Using a space heater can be a good way to boost the temperature in a small, drafty room—and it could be less expensive than cranking up your central heating system. But a space heater is economical only if you use it judiciously.

What is the safest heater to leave on overnight?

What is the safest heater to leave on overnight? While it's not recommended to leave any space heater on if you're not monitoring it, oil-filled, radiant space heaters are considered safer than ceramic convection (hot air) types, according to Roberson. Both of these options are safer than open-coil heaters.

What room do most house fires start in?

Where are home fires most likely to start? Home fires are more likely to start in the kitchen than any other room in the home. The second leading cause of home fires are heating sources like wood stoves, and fireplaces. Fires caused by smoking are the leading cause of deaths.

What causes 90% of all fires?

Whilst they can start naturally, see Information note - Wildfire, it is estimated that 90% of all wildfires across the globe are caused by humans. About 30% of those are started as a deliberate act of arson, whilst 70% are started accidentally or as a direct result of human carelessness.

How do house fires start at night?

Electrical bedroom fires are often due to faulty or overtaxed wiring or malfunctioning lighting,6 but bedroom fires also start with cords, space heaters, or electric blankets. Bedding, carpeting, draperies, and other creature comforts of your bedroom are often the first items ignited in a fire.

How long can I leave a space heater on?

Recommended Usage Times. During the Day: It's generally safe to run your space heater for 6 to 8 hours during the day while you're home and active.

Why do space heaters catch fire while sleeping?

Portable heaters can cause fires if they are placed too close to combustible materials, such as drapes, furniture or bedding, so make sure to place them at least three feet away from these materials.

Do space heaters use a lot of electricity?

Space heaters can take anywhere from 750 watts to 3,000 watts to operate. Large space heaters take immense amounts of energy to run. However, those are most likely used only in commercial and industrial settings. The average residential space heater has two main heat settings, low and high.

What happens if you leave a heater on for too long?

Fires are one of the biggest risks associated with leaving electric heaters on all night. If an electric heater has frayed wiring or malfunctions, then there is a high chance of it igniting. Electric heaters also make the air in the room really dry by conducting a lot of heat.

Is it bad to sleep next to a space heater?

“No, it's absolutely not safe to use a space heater at night,” states Glenn Gault, CEO at Gault Heating & Cooling. “It's not even safe to leave your space heater running when you leave a room for just a few minutes.

Will leaving a space heater on cause a fire?

Space heaters can pose potential risks if not used properly. They have the potential to cause fires if placed too close to flammable materials or left unattended. Additionally, using extension cords that are not rated for the heater's power can increase the risk of overheating and electrical hazards.

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