A device that is placed of one's vehicle that when plugged into an electrical socket with a plug heats up the interior of the car like a small space heater. Used in any part of the world where the temperature drops below freezing.
The interior heater can have a timer and be set to come on or keep the car warm even at extremely cold temperatures. It is usually seen as an electrical cord sticking out from under the hood of a car in Canada or the states that border Canada.
It was really cold last night, but my car was toasty warm because I had the interior heater on.