9 Places You Should Never Put a Space Heater, According to Fire Safety Experts

Freezing temperatures have overtaken many parts of the country this winter, prompting people to crank up the heat in their homes. But when some rooms or areas of the home just don’t feel warm enough, it’s not uncommon to turn to a space heater to provide an extra boost of warmth. Knowing how to use one properly is not just important, though—it’s crucial to your health and safety. Without care, these small appliances can become a fire hazard. To keep you and your loved ones safe, we spoke to fire safety experts about where exactly in your home you should never place your space heater.

In the Bathroom

Stepping out of the shower into a warm bathroom sounds like a dream, but it's best to keep your space heater out of this room. "All it takes is a splash from your handheld shower head or bathroom faucet, and suddenly you have an electric appliance cooking itself with wet components," says Lo Choe, owner of Aura Fire Safety. "Waterproof doesn’t always equal shockproof. That outlet casing will melt, cords can arc, and your wall could be smoldering by the time you realize what’s happening."

Near Flammable Products

Flammable products, such as open paint thinner, hair spray, and cleaning supplies, should be kept away from space heaters—even if you trust yourself not to spill them. "You don’t have to drip any liquid on the heater," says Choe, explaining that the heater vent can draw air and vapor in through its heating element. "The vapor is enough to ignite once it contacts hot surfaces. It doesn’t take much for the mixture of air to reach flammable limits," she says.

Close to the Main Thermostat

Placing your space heater too close to your home’s thermostat could spell trouble for your entire house. The space heater can make your thermostat think the entire house is warmer than it is, when it’s really just that one spot near the thermostat sensor, causing your furnace to stop running as often as it needs to. "There will be no heat in the house, so the pipes in the bedrooms, basement, and the rest of the house [could] freeze,” says Russ Teaca, director and lead technician for Reliable Heating and Air.

On Rugs or Carpets

Space heaters should always be placed on a hard, flat surface, such as a wood floor, brick, or concrete, says Teaca. This allows for proper airflow underneath the unit, something that generally can’t happen if the space heater is placed on a soft surface, like a rug. "If the machine doesn't get enough airflow, the internal part quickly gets too hot because the heat isn't being pushed out," he says. "You are depending on a safety plan to keep the fire from starting, even though most new units have thermal timers that shut them down." Teaca also notes that the heat from the space heater can melt fake rug strands or burn the base of the unit before it turns itself off.

In the Corner of a Room

You might think you’re keeping your space heater out of the way by placing it in a corner, but you’re actually restricting air flow. "Most portable heaters require 2 to 3 feet of clearance around all sides to dissipate heat properly," says Choe. "If heated air can’t exit through the back vents, then it will start cooking the wires internally. There have been cases on back panels of cabinets where space heaters have been sitting for hours and reached 160 degrees Fahrenheit.”

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Next to Soft Bedding or Curtains

Placing a space heater in a bedroom is pretty common—that little boost of warmth can make the difference between a warm, cozy rest and bundling up in blankets to keep a chill away. But be extra careful about where you place it, as placing a space heater too close to your bed or near curtains is a recipe for a fire.

​"When a space heater is pushed next to blankets, comforters, or pillows, it radiates heat onto materials that absorb heat," says Choe. She adds that fabrics retain heat much longer than most people realize and can dry out and become brittle within 1 to 1.5 feet of radiant heat. "Bedding fires typically start quietly, then rapidly grow when flames reach multiple layers," she says.

Under Your Desk

Resist the temptation to place a space heater under your desk for extra warmth, even if you’re a little chilly while working all day. When you put a space heater under a desk and cover its sides, the heat builds up quickly instead of moving around, says Teaca. "This dries out and ruins solid wood furniture and puts the heat source too close to clothes, hanging wires, and trash cans, which is not safe. There is a high chance of fire in a small area," he notes.

Next to Outlets With Multiple Power Strips

Space heaters draw a lot of electricity and plugging them into an outlet that is already supplying power to a packed power strip may cause the internal wires to heat up inside your walls. That confined space has nowhere for that heat to escape, posing a fire risk, Choe says.

In a Doorway or Hallway

Doorways or hallways are high-traffic areas that aren’t suitable for space heaters. Pets, children, and other passersby can push the space heater out of its initial spot. "A small angle change can cause your heater to overheat because the air isn’t flowing like it's manufactured to," Choe says. She also notes that running extension cords can create a trip hazard. "Electrical burdens with physical threats (trip hazards) are asking for disaster," she says.