As temperatures drop across the northern hemisphere, millions of people rely on space heaters to stay warm. But firefighters are urging everyone to be extremely cautious when using them — especially when it comes to how they’re powered.

According to the Umatilla County Fire District in Oregon, you should never plug a space heater into a power strip. These devices simply aren’t built to handle, the high electrical demand. “They can overheat or even catch fire,” the department warned.

The risk is real — in Ohio, a space heater plugged into a power strip ignited a couch, quickly consuming an entire home in flames. Space heaters can reach up to 600°F, making them a serious fire hazard if not used properly.

To use them safely, follow these firefighter-approved tips: Plug directly into a wall outlet — never into a power strip or extension cord, Keep a clear 3-foot radius around the heater, free from furniture, curtains, or anything flammable, Only use space heaters when you’re in the room — never leave them unattended or running while sleeping, Place heaters on flat, stable surfaces — not on furniture, rugs, or elevated surfaces, Fires caused by space heaters are preventable.

Taking a few simple precautions can keep your home warm and safe this winter.