It's The Middle Of Winter And Very Cold, Yet I

It's the middle of winter and very cold, yet I find myself sweating a lot or more than usual. Ive tried using less layers of clothing going out, but even in a hoodie and pajamas I'll take my dog outside for not even 15 minutes an barely walk and when I come in I'm dripping off my forehead. If I walk a mile to the store my whole shirt gets soaking wet, why am I sweating so much in ice cold weather?