Don’t Run a Space Heater Overnight Leaving your space heater running all night long while you sleep is a no-no. If the unit overheats, tips over, or short-circuits overnight, a fire could break out while you’re fast asleep.
How long can you leave space heater on?
If you have an upscale heater, you can easily leave it on for 10 hours or more without an issue. Most fire safety specialists suggest heating up a room for two to three hours before you sleep, then turning it off.
