Hadn't thought about that but I usually leave the heat at the defroster. Makes sense though...Damn that sucks dude. At least it didn't happen when you were out in the snow like an hour away from home. My opinion is that this happened because of constant heat blasting on your feet in your vehicle. Im saying that cuz the same happened to me in 3 different brands of boots. I stopped having the heat go to my feet in my work truck and personal car and this stopped happening.