I HAD THE SEAT HEATER ON, DRIVER'S SIDE FOR APPROXIMATELY 30 MINUTES. THE HEATER OFTEN GETS EXTREMELY HOT, SO I DID NOT THINK ANYTHING WAS DIFFERENT. HOWEVER LATER UPON EXAMINING MY BACK IN THE MIRROR, I HAD A HUGE BURN ON MY BACK THAT LOOKED LIKE I HAD LAID DOWN ON A BBQ GRILL. THERE WERE VERTICAL LINES WHERE THE SEAT HEATER HAD BURNED ME, INTERRUPTED BY SECTIONS WHERE THE CUSHION IS UPHOLSTERED, AND NOT TOUCHING MY BACK. THE BURN IS APPROXIMATELY 12 INCHES LONG AND 8 INCHES ACROSS. *JS