Can you plug a space heater into an extension cord?
No. Plug a space heater directly into a wall outlet, never into an extension cord or a power strip. Extension cords and power strips can overheat and start a fire.
Why not a cord or power strip
Power strips aren’t designed for high power loads such as space heaters, which can easily go past the amp rating on many power strips. The watts to amps calculator turns a heater’s watts into amps.
Heavy-duty extension cords are no exception. Lasko’s manual for its model 106 heater also rules out surge protectors, multiple outlet adapters, cord reels and outlet-type air fresheners.
What to do instead
Set the heater up near a wall outlet.
Don’t plug anything else into the same outlet. That can overload the circuit.
Keep the heater’s cord out from under rugs and carpeting.
Where there’s no outlet near the spot you want to heat, an electrician can add an outlet.
Other heater safety
Keep all sides of the heater at least 3 feet from beds, curtains, sofas, papers and anything else that can burn.
Turn the heater off and unplug it when you leave the room or go to bed.
If the heater’s cord or plug gets hot, unplug the heater and contact an authorized repair person. If any part of the outlet is hot, call an electrician.
Common questions
Can I plug a space heater into a surge protector?
No. A surge protector is a power strip with surge protection parts added, and power strips are not designed for high power loads such as space heaters.
Does the plug need to fit tightly in the outlet?
Yes. Check often that the plug fits snugly in the outlet. If it fits loosely or gets very hot, unplug the heater. The outlet may need replacing by a licensed electrician, and a hot plug also means the heater should go to an authorized repair person.
The advice comes from the CPSC and the NFPA, a heater maker’s own manual (Lasko) and an OSHA letter on power strips. Checked against published data from CPSC, NFPA, Lasko and OSHA.
See all 6 sources
US Consumer Product Safety Commission, “Keep Warm and Safe This Winter” (January 2026): space heaters directly into a wall outlet, three feet, off when sleeping; portable generators at least 20 feet from the home