chefisaac

anyone use them on their commute in the cold weather?

2manybikes

I don't commute but I have used them a lot on rides.

One needs to be sure there is enough room in your shoe with them in there. Tight shoes can restrict you blood flow a little and that can make you colder.

They need the oxygen restriction of being in your shoe to not get too hot too fast. But they need a little air to work.
When you get to your destination you can stop the reaction by putting them in a zip lock sandwich bag, and squeezing out all the air. That way if you don't use them completely you can use them again.

blakcloud

I use them on the coldest winter days when commuting. It has to be -20 Celsius or colder before I put them in. My winter commute is only 45 minutes and they work well enough. If I had to use them on a daily basis I don't think it would be cost effective.

revolator

I usually by a box of hand warmers from Costco. They come with some foot warmers. But I usually use the hand warmers and place them around the ankle area inside my double socks, when I've used up the foot warmers.