Do you worship the heated seats in your car, blissfully toasting your way to work every morning? Well, you might want to proceed with caution. Two case studies published in the journal Archives of Dermatology report that the bum-warmers can cause brown or patchy skin, known as “toasted skin syndrome.” In both cases, women cranked the seat heat for at least 45 minutes every day (hello, commute) and subsequently developed skin-discolorations on their legs. The condition isn’t life-threating, but it’s not to be taken lightly either. The skin changes are likely due to changes in the blood vessel and pigment cells, which can get worse with more exposure. But remember, seat-warmers can get too hot at times. Consumer Reports reported last year that some were so hot, drivers were pursuing legal action for serious burns. So drive comfortably and warm, of course, but don’t over-toast yourself en route either!