Fire safety experts and consumer protection agencies, including the Consumer Product Safety Commission, strongly advise against leaving a space heater on all night. The risk of a fast-moving fire occurring while you are asleep is significant, as you may not wake up in time to react to danger.
If you use a space heater be sure that you have a 3-foot radius free from anything flammable when using it. Don't leave your space heaters on overnight. If you leave the room, turn off the heater when you leave. Stay safe and stay warm!
Most indoor heaters tend to dry out the air, lowering indoor humidity levels. Dry air can cause irritation to the respiratory tract, leading to symptoms like dry throat, cough, and nasal congestion. For individuals with chronic respiratory diseases like asthma or COPD, low humidity can exacerbate symptoms.
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.
Recommended Usage Times
At Night: If you choose to use your space heater overnight, it's best to limit its operation to 4 to 6 hours on a lower setting.
Space heaters
One small space heater plugged in 8 hours a day can add about $50 to your monthly electric bill. Space heaters are a great way to increase the temperature in one room for a short period of time, but keep in mind that they can be costly to run and will result in a higher bill.
Is 72 a good temperature for heat in the winter? While slightly higher than the typical energy-saving range of 68°F–70°F, 72°F still offers a reasonable balance between comfort and efficiency.
The Risk of Space Heater Fires
One third of fires in the home are caused by space heaters.
While cozy heat sources can make winter more comfortable, prolonged or repeated heat exposure can cause lasting skin damage. Be mindful of how long you're using heating devices, and give your skin time to cool off between uses.
Only central heating systems (like a furnace) are officially deemed 100% safe for overnight use. If you must use a portable space heater, select oil-filled radiators or modern smart ceramic heaters equipped with automatic tip-over shut-offs, thermal sensors, and built-in timers.
For individuals with COPD, temperatures below freezing (32°F / 0°C) are considered too cold and can trigger severe flare-ups, chest tightness, and shortness of breath. Even temperatures dropping below 40°F (4.4°C) can cause the dry, chilled air to irritate overly sensitive airways.
It takes time for your home to warm up and cool down. If you're not sure how long it takes, try turning the heating on about 30 minutes before you need it. You should turn it off 30 minutes before you'll stop needing it.
The most significant downfall of indoor heating is that it causes the air to dry out. Our lungs have to stay moist in order to function properly. Exposure to dry air for a prolonged period of time can cause wheezing, shortness of breath, and other respiratory problems.
Portable Space Heaters Can pose a serious fire risk if left unattended. Always make sure to turn them off when leaving the room or going to sleep. Following these safety tips can help prevent winter fires and keep your home safe and warm.
It is generally not recommended to sleep with a space heater on. While modern electric models with safety features are much safer than older units, leaving a heater running unattended poses severe fire hazards, carbon monoxide risks (for fuel-burning models), and can dry out your airways.
Electric heaters of any type are unsafe to leave running overnight because they carry a significant amount of risk. 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.
What is the safest heater to leave on overnight? It's not recommended to leave any space heater on if you're not monitoring it. But if you must, 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.
The safest indoor space heaters are oil-filled radiators and ceramic heaters with built-in safety features. Look for models certified by organizations like UL or ETL that include:
Consumer Reports tests space heaters primarily on room heating ability, spot heating, and strict fire and safety criteria, such as overheat protection and tipping tests. Highly rated models often cost around $75 to $100 and feature auto-climate control and tip-over shut-offs.
The most basic rule about space heaters is to keep everything three feet away from them. That includes you because too close contact with a space heater can burn you. It also includes blankets, fabrics, pets, children, and anything flammable.
Space heaters do not technically remove moisture from the room, but they significantly lower the relative humidity of the air. As the air warms up, its capacity to hold moisture increases, causing it to aggressively absorb water vapor from your skin, nasal passages, and environment.
If left unattended or used improperly, these devices can become dangerously hot. Overheating can occur if the heater is left on for extended periods or if it is used in a confined space without adequate ventilation. This can lead to the internal components of the heater breaking down, potentially causing a fire.
Cooking is the leading cause of house fires in the United States. According to NFPA research on home cooking fires, cooking-related incidents account for the largest share of residential fires and injuries. Unattended cooking is the most common contributing factor.
A Leading Cause of Fires
The Consumer Product Safety Commission reports that approximately 1,200 fires a year are caused by portable electric space heaters.
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.