Heating season has officially arrived, so you’ve likely already once again become accustomed to the hum of your furnace. And if your home has heating issues, you may have also broken out a space heater to stave off dropping temperatures.

But while space heaters are often used to provide an extra boost to your heat, they do come with risks. According to the National Fire Protection Association, space heaters account for about 43% of U.S. home heating fires, and 85% of deaths related to home heating fires.

“Space heaters do present a potential fire hazard, but they can be used safely,” says NFPA communications manager Susan McKelvey. “Many fires that occur are because of human error, so if you can realize where those behaviors can contribute to a home fire, you can take steps to minimize those risks.”

So how can you use space heaters without burning your house down? Here is what you need to know:

First: Do you really need one?

Space heaters are a convenient way to warm up your home, and in some cases — like if your furnace conks out — they may be necessary. But overall, they should be seen as a “last resort, not a first resort,” to solving a heating problem, says Steve Luxton, executive director and CEO of the Energy Coordinating Agency, local energy conservation nonprofit.

That’s especially true in Philadelphia, which has older housing stock with many using built before 1950. Older homes, Luxton says, often have older wiring that isn’t designed to handle the loads that a constantly running space heater demands — particularly in conjunction with other electrical appliances. Generally, he adds, space heaters pull about 1,500 watts of power per hour, which can be problematic for old wiring.

“You’re pulling a lot of energy through an old line, and it’s probably not the only appliance on that line because these homes were underserved with electrical outlets,” he says. “Electricity develops resistance, and that translates to heat,” which can cause an electrical fire.

But even if your home has newer, updated wiring, there’s another factor to consider: Cost. Electricity, Luxton says, is much more expensive to use as a heating fuel than something like gas, which can translate into higher bills during heating season if you’re constantly using a space heater. Instead, you might just consider turning your heat up a couple of degrees — or, if there’s an issue with your system, you could try having it fixed instead, such as by bleeding radiators or removing a blockage in your heating ducts.

“It will be cheaper to get a heating contractor out there to figure out why this space isn’t heating up correctly, instead of using a Band-Aid, which is what the space heater is,” he says.

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How to use a space heater safely

Start with the manual, which will have safety information for that specific model, says Philadelphia Fire Department firefighter Namor Brown.

Here’s the best advice, according to Brown, Luxton, and Electrical Safety Foundation International:

  • Never use an extension cord. Many are not rated to handle the power demands of heaters, and can overheat and cause a fire.

  • Keep flammable objects at least three feet away from the space heater.

  • Plug it into a grounded circuit.

  • Avoid putting it in a place with a lot of traffic where it can get knocked over.

  • Turn off space heaters when sleeping or leaving a room.

  • Never leaving them running when unattended.

  • Don’t plug in other electrical appliances into the same outlet.

  • Check the plug before each use to make sure it is not damaged or frayed.

  • Place the space heater on a flat, level surface and avoid putting it on carpet.

  • Install smoke alarms on every floor of your house, and test them once per month.

How to buy a space heater

If you need to use a space heater, there’s no shortage of them on the market — and they come in a variety of types, including oil or water-filled radiators, fan-forced heaters, ceramic heaters, and infrared heaters. No matter when you end up getting, though, there are a few elements to consider before you buy.

  • Check that it bears the mark of an independent testing laboratory, such as Underwriters Laboratories (UL), the Canadian Standards Association Group (CSA), or Intertek, McKelvey says. These groups test electrical products and equipment to make sure they meet certain safety standards, and having their mark means a product meets those standards.

  • Look for a model that has an automatic shutoff mechanism, so that it will turn off if it is tipped over, according to the Federal Emergency Management Agency. Space heaters that have both a thermostat that allows you to set the temperature, as well as overheating protection that prevents it from getting too hot, are a good idea, too, the NFPA indicates online.

  • And while Luxton would prefer you don’t use a space heater, oil-filled radiators are his pick if you need to use one. That type of space heater, he notes, doesn’t “get hot enough to make something catch fire” when touched, and can be fairly effective at heating up a room.

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