I STARTED VEHICLE AND TURNED ON THE DRIVERS SIDE HEATED SEAT SWITCH PRIOR TO CLEANING THE SNOW AND ICE OFF WINDOWS AND HOOD AFTERWHICH I LET MY COWORKER CLEAN HIS VEHICLE OFF. I WENT BACK TO MY VEHICLE TO SMELL SOMETHING BURNING AND NOTICED THE LEFT SIDE OF THE SEAT SMOLDERING THROUGH THE CLOTH. I TURNED THE SWITCH BACK OFF AND WIPED THE AREA WITH SNOW THUS STOPPING THE IMPENDING FIRE. I WOULD ESTIMATE THE TIME RUNNING/WARMING UP; TO BE APPROXIMATELY 6 MINUTES. *TR