Extension cord safety

Lower number means heavier wire

Extension cord wire gauge determines how much current it can safely carry. Lower gauge numbers mean thicker wire and higher capacity. A 12-gauge cord handles heavier loads than a 16-gauge cord.

For appliances like refrigerators, freezers, and space heaters, use a 12-gauge or 14-gauge cord rated for the load. A 16-gauge cord is suitable only for light-duty items like lamps and phone chargers on short runs.

Overloading and daisy-chaining

CPSC reports that overloaded extension cords cause roughly 3,300 home fires per year. An overloaded cord overheats, melting insulation and igniting nearby materials. Signs of overload: the cord feels warm or hot to the touch, the plug is discolored, or you smell burning plastic.

Never daisy-chain (connect one extension cord to another). This increases total resistance, generates heat at each connection point, and defeats the cord's built-in overload protection.

Use the right cord for the environment

Outdoor cords are built with weather-resistant insulation and are marked with a "W" on the jacket. Using an indoor cord outdoors exposes it to moisture, which can cause short circuits and shock. Using an outdoor cord indoors is safe but unnecessary.