Summer is nearly here, and the temperatures are climbing. If you don’t have central air, you might be thinking about installing an AC unit in your window to stay cool. Before you channel your inner Bob Vila, heed the following words of wisdom from Gothamist: Don’t connect the unit to an extension cord. If you do, you might burn your house down.

Ever noticed that the cord connected to your AC is thick and short? That’s because ACs draw a lot of electrical current—way more than devices like, say, computers. Normal extension cords can’t handle as much electricity as permanent wiring, so if you use one to plug in your AC unit, the cord can overheat and start a fire. The same goes for attaching extension cords to other large appliances, like refrigerators or freezers. 

What should you do, then, if your outlet is too far away from your window? Try a fan (with a properly-rated extension cord, of course), or consider buying a freestanding AC that you can position near the outlet of your choice. And if all else fails, you can go shopping for a special, heavy-duty extension cord that’s designed to be safely used with electricity-hungry appliances. They’ll be shorter, with 12 or 14 gauge wire and higher amp ratings. The lower the gauge, the more electrical current (amps) the wire can carry.

Sound too confusing? Simply give the electricity rating listed on your AC unit (or in its instruction manual) to an electrician or hardware expert. They’ll help you select a cord that’s safe.

If you live in a cooler area, you might not even need an AC to control your home’s heat. To help your fans get the job done, also keep your blinds closed to prevent unwanted heat from coming in through windows, swap incandescent light bulbs for compact fluorescent lamps, and cook outside on a grill instead of in your kitchen.

Believe it or not, two-thirds of all electrical fires begin in plugs or cords on appliances like refrigerators, air conditioners, or lamps [PDF]. Play it safe—and just in case your neighbors aren’t, consider renter’s insurance.

[h/t Gothamist]