How do I choose a safe extension cord for a space heater?

Check the wire gauge — look for 12 AWG or lower, ignore marketing labels like “heavy duty.” Space heaters pull 12–15 amps continuously, and most household cords (16 AWG or thinner) can overheat and cause a fire. Use 12 AWG for 15 amps, 14 AWG for 12 amps, and never buy a cord that doesn’t clearly show the AWG number.