5 Things to Know About Flat Extension Cords Under Rugs

Flat cords are designed for under-rug use, but only if the package says “carpet” or “under rug.” Shape alone doesn’t guarantee safety.

Round extension cords are a fire hazard under rugs. They’re thicker, trap heat, and are not rated for covered use.

Flat cords dissipate heat better than round ones, making them safer when covered. But they typically carry less current—13 amps versus 15 amps for standard round cords.

Never run a space heater through a flat cord under a rug. That’s unsafe regardless of the cord type.

For baseboard use, either cord works. Flat is easier to hide, but round is more durable for long-term visible runs.