Use Extension Cords Safely By Learning Warning Signs

an extension cord

that could not handle the power load from an air conditioner ignited a couch. Engineers who test electrical devices said it is important to know the warning signs.

Whether it is a work boot or a firefighter's coat,

Underwriters Laboratories

tests more than 18,000 products. Among them are electrical cords. Cords must survive the tugging, pulling and shock treatment of 20 different safety tests to earn approval.

"Sometimes you can touch it and it's so hot and you have to pull your hand away. That's when you discard them," engineer Brian Baker said.

Baker said a circuit breaker should trip when a cord overheats, but several factors add to the fire risk. Older cords that show signs of damage heat up faster. Length can also contribute to an overloaded cord.

"As you get longer, you have more resistance. Thus, the temperature is going to increase," Baker said.

You should also check the warning label. And you are never supposed to use an extension cord that is coiled.

Investigators say the extension cord in the Chatham County fire was covered by a carpet and furniture, which is another big fire hazard. One final note: you should always check the extension cord's amperage to see if it can handle the power load of the appliance you plan to plug into it.