Causes of Warmth If you can feel the warmth on your extension cord, something is wrong. Overloading the cable with more items than it can handle may cause a hot extension cord. However, this problem can also be caused by poor or worn-out insulation. Unplug the cable immediately and discard it.Click to see full answer. Considering this, is it bad if an extension cord gets hot?Choose the right extension cord for the job, and use it as specified. Extension cords can overheat and cause fires when used improperly. Overheating is usually caused by overloading or connecting appliances that consume more watts than the cord can handle. Damaged extension cords can also cause fires.Beside above, what causes a plug to overheat? The most likely problem causing an overheating electrical outlet is an overloaded circuit. Loose or damaged wiring can also cause a buildup of heat in an electrical outlet. You might notice short bursts of sparks when you plug in appliances, which is a warning that the wiring may not be in the best condition. Thereof, why does the cord on my electric heater get hot? This amount of electricity may cause the cord to become warm – this is normal. You should be able to put your hand around the cord and feel that it is warm to the touch, but it should not be too hot to hold. If the cord is excessively hot, there may be a problem with the outlet the heater is connected to.Can extension leads catch fire?Never overload an extension lead by plugging in appliances that together will exceed the maximum current rating stated for the extension lead. This could cause the plug in the wall socket to overheat and possibly cause a fire. Some block adaptors do not have a fuse, which increases the risk of overloading and fire.