I had some HotHands chemical hand warmers that came free with a pair of gloves. They've been riding in my seatbag. Went for a 20-mile ride today in the cold and snow. I was wearing sneakers and thick socks. I hate wearing heavy boots and avoid it whenever possible. My toes started getting a little nippy - nothing serious. Then I remembered the HotHands. I put one in each shoe and MAN was that nice. I'm going out to get some more.