Are Space Heaters Safe? Here’s How Not to Start a Fire

Space heater safety is a lot better than it used to be. Modern space heaters are heavily regulated, especially regarding exposed heating elements and automatic shut-off switches to prevent overheating when a heater tips over or has its vent covered by an errant drape.

I tested these protections on each of the WIRED Gear Team’s favorite space heaters, roughly knocking heaters over and standing warily by as I swaddled each heater in a cotton sheet atop concrete. Any heater that we recommend performed admirably on these tests, shutting down or modulating its power output to keep from overheating.

The statistics bear out the safety improvements to space heaters: The number of fires due to heating equipment in the United States has dropped by more than 40 percent in the years from 2000 to 2020, according to a study by the National Fire Protection Association.

But heating devices still reward great caution, as do all devices that pull a lot of energy over long periods. The vast majority of residential heating fires start with actual fire, according to the United States Fire Administration—specifically in fireplaces and fuel burners. But portable space heaters nonetheless accounted for more than a thousand fires in the US each year from 2017 to 2019, according to the USFA’s numbers.

This accounted for just 3 percent of heating fires overall, but these led to more than 40 percent of fatalities, in part because portable heaters tend to be placed precisely where people live and sleep, and because the resulting fires are far more likely to be unconfined.

So treat your space heater with the caution and skepticism that it deserves. Here are some quite simple space heater safety tips, courtesy of the fine federal experts at the USFA, the Consumer Product Safety Commission (CPSC), and the Association of Home Appliance Manufacturers (AHAM).

Observe the “3-foot rule.” The CSPC has a simple rule of thumb: Keep your space heater at least 3 feet away from anything flammable—pretty much the same amount of space that’s considered courteous between two people during polite conversation. Flammable materials includes bedding, drapes, furniture, the dress you were going to wear, stray socks or stockings, your food delivery bag, and that great book you’ve been reading. Generally, also avoid placing flammable stuff like pillows or drapes in a spot that might potentially fall atop the space heater or drape over them.

Be especially wary of really, really flammable things. Maybe you don’t need to be told this. But AHAM recommends that you keep your space heater far, far away from very flammable things like paint, gasoline, aerosols, and books of matches. Heating up things like this with dry air is asking for trouble.