The best way to use a space heater is to heat up a cold room in the house, says Mary H.J. Farrell, a senior editor for home and appliances for the product-testing nonprofit Consumer Reports.

Space heaters are not efficient ways to heat the whole house, nor will they save you when the power goes out. They’re perfect, however, for when you want to keep the whole-house temperature down but warm up the room you’re in. They are “a convenient way to quickly raise the temperature of an area or a drafty room,” says Tom Larsen, owner of House Doctors of Manassas, a handyman service in Northern Virginia. “Most people, say if an office is chilly, they’ll use it for that local area where they’re sitting or working instead of turning up the temperature on the whole house.”

Full Story