I tried it last year. Rode to work (14mi) with temps at 0F and windchills -15. Of course I wanted to see the look on everyones face when I rode in. I got about 7mi when I had to stop. The foot warmers in my boots were SO warm they made my feet sweat. The temp was cold enough to freeze the foot warmers. When I stopped, my feet were really cold. I took the foot warmer out and literally skipped it across the pavement. I had to walk a while to get circulation back in my feet.

I'm much more careful with the cold temps now. I'll ride in negative temps....just not to work. A short trip around the neighborhood or to the store. It can really be dangerous.

It would suck to freeze a toe or finger and not be able to ride when the weather is nice!