Are space heaters safe? Simple mistakes can easily start a deadly fire, experts warn

The fire that killed 17 people and injured dozens more in the Bronx over the weekend has become yet another deadly blaze blamed on a space heater, a common household device that has long concerned safety experts.

"Space heaters can be effective tools for heating up a small space, but you have to use them with care and caution," said Susan McKelvey, a spokesperson for the nonprofit National Fire Protection Association.

Experts say the Bronx fire is not an isolated incident. Space heaters – which by some definitions can include certain types of stoves and fireplaces, in addition to portable electric devices – are common sources of deadly fires.

U.S. Fire Administrator Lori Moore-Merrell said nearly half of fatal fires involve space heaters: "That’s how dangerous they are." Moore-Merrell spoke by phone while returning from visiting the site of the Bronx fire, which she called a "devastating tragedy."

Portable heating devices often serve an important function: keeping people warm inside cold areas with poor heating. In the Bronx fire, residents of the 19-story high-rise said the building's heating worked but some units were drafty.

When using space heaters, simple safety mistakes can quickly turn deadly.

Here's what to know:

Portable heaters cause hundreds of fires each year

Portable heaters are involved in about 1,700 fires per year, resulting in about 80 deaths and 160 injuries, the Consumer Product Safety Commission estimates.

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National Fire Protection Association data from 2014 to 2018 links heating equipment broadly to 50,000 fires, 500 civilian deaths and 1,350 civilian injuries on average every year. Space heaters – which the association defines as including heating and wood stoves, portable heaters, local furnaces and fireplace inserts – are the type of heating equipment most often involved in home heating fires, the association said in a press release.

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Now, amid the winter months, is the most dangerous time of the year. Nearly half of home heating equipment fires are reported during the months of December, January and February, according to the association.

How do space heaters start fires?

National Fire Protection Association data shows about half of home heating fire deaths are caused by having heating equipment too close to things that can burn, such as upholstered furniture, clothing, mattresses, or bedding.

That's why heaters should be kept at least 3 feet away from anything that can burn.

"Space heaters really do need space," said Alexander Hoehn-Saric, chair of the U.S. CPSC.

Safety officials recommend placing heaters on a solid, flat surface away from children, foot traffic, or exits, plugged directly into the wall outlet. Never use an extension cord, the National Fire Protection Association says.

"If it’s plugged into an extension cord that’s not designed for the load that a space heater draws, in terms of energy, it can overheat, potentially, and spark a file," Hoehn-Saric said.

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How long can a space heater be on?

Running a space heater for too long can also cause a fire, McKelvey said. It's important to follow a manufacturer's instructions on how long a space heater can run, she said.

"If you’re using a space heater, it’s typically to supplement heat. You either don’t have heat or sufficient heat in your living environment or home, so there’s a tendency to let them run longer. But they’re not designed for that," Moore-Merrell said.

Can you sleep with a space heater on?

Space heaters should be turned off and unplugged when you leave the room or go to bed, the National Fire Protection Association says.

McKelvey cautioned against using space heaters in bedrooms or when tired. "If you fall asleep – it’s too dangerous. Use them in spaces where you are awake, where you can monitor them carefully," she said.

Moore-Merrell offered similar advice: "Treat them like a burning candle."

Can a space heater make you sick?

Space heaters can also present a hyperthermia, or overheating, hazard to consumers, which can be fatal, a CPSC report found. Children, people with disabilities and senior citizens "may be more susceptible because of their limited ability to act or react to the elevated ambient temperature," the report said.

"DO NOT leave space heaters running unattended in a confined space around infants, or individuals with reduced physical, sensory or mental capabilities," the commission warns.

What to look for in a space heater

There are different types of space heaters, including oil or water-filled radiators, fan-forced heaters, ceramic heaters and infrared heaters. For fuel-burning space heaters, it's important to always use the right kind of fuel, specified by the manufacturer, the association says.

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The association recommends selecting a heater with a thermostat, overheat protection, the seal of a qualified testing laboratory and an auto shut-off that turns the heater off if it tips over.

"If you don't buy one that has been certified, then you're running the risk of not meeting the voluntary standards that are out there," Hoehn-Saric said.

Over time, it's important to check space heaters for wear and tear, McKelvey said. "If the knobs aren't working properly or the wire is frayed at all, it won’t work properly. You want to ensure the equipment is in good working condition," she said.

Hoehn-Saric encouraged people who have space heaters to visit the CPSC's website to make sure the heater hasn't been recalled.

This article originally appeared on USA TODAY: Space heater fire in Bronx renews concerns: Are space heaters safe?