Dec 6, 2015 By The Editors Of consumer Reports® 3 min read

Even if you’ve made the effort to insulate your attic and weatherstrip your windows, there may still be a room — or a person — in your house that is difficult to keep warm, says Consumer Reports.

The most important decision to make when buying a space heater is to know whether you need spot heating (just bathing yourself in warmth) or something that heats a room — a drafty office or bedroom, for instance. Despite claims on the box, not every space heater does both jobs well.

And no matter which you choose, keep in mind that using a space heater won’t necessarily save you money. Electricity is the most expensive way to heat, so space heaters make sense only when used as a supplemental or occasional heat source.

Here are performance factors Consumer Reports suggests considering, and some good model choices from its tests:

n Best for spot heating. Testers measure the “spot” heating ability of a heater to directly warm a person sitting 4 1/2 feet away in 15 minutes. Top spot-heating picks include the Dyson AM05, $400, and the bigger Honeywell HZ-980, $190.

n Best for room heating. Consumer Reports’ measure of success in room heating tests is to gauge the effectiveness of the heater to warm up a 12-by-17-foot room with 8-foot ceilings in 15 minutes. Testers liked two models from Vornado and two from Heat Storm.

n Best at doing both. Space heaters that earned top marks for both spot heating and room heating include the DeLonghi DCH1030, a bargain at only $42. (At that price, you give up some features.)

Make Sure It’s Safe

About 25,000 house fires and 300 deaths are attributed to space heaters each year, mostly caused when a heater is placed too close to curtains, bedding and upholstered furniture. In addition, 6,000 people end up in the emergency room with burns from touching a heater’s hot surface. Consumer Reports notes other safety features that count:

n Make sure the heater you buy carries a safety certification label from an independent testing organization, such as the UL mark from Underwriters Laboratories, the ETL label from Intertek or certification from CSA International.

n A smart sensor that shuts off a heater when it overheats is a must. You’ll also want a tip-over switch that does the same if the heater is knocked over.

n Most space heaters do not come with a ground fault circuit interrupter plug, which prevents electric shock, so manufacturers warn that they not be used around water.

Fancy Features

That Count

You want a space heater that’s great at its primary job, but there are other features that enhance the ease of use.

n Fan with multiple speeds. Fans help distribute heat more quickly. Some models oscillate for more even heating. Slower fan speeds are less noisy.

n Timer. This moneysaving feature helps ensure that the heater is operating only when you need it.

n Adjustable thermostat. Many space heaters have one, but others have just high-low heat settings, so the temperature is more difficult to adjust.

n Remote control. Space heaters are intended to sit on the floor. A remote can help prevent having to bend over to fiddle with the controls.

n Weight. Check the weight on the box if you plan to move the heater.

n Warranty. Look for a model with a three-to-five-year warranty.

For more information, visit ConsumerReports.org.