DESCRIPTION: Cold feet are hard to ignore on a long day outside, and this whole sole warmer covers the entire foot, not just the toes, for up to 6 hours. It’s ultra thin and air activated, so it slips into a boot or shoe and starts producing heat once the packet is opened. Size S/M is made for men’s shoe sizes 4-7 and women’s shoe sizes 5-8, and the activated charcoal helps absorb odour, which makes it a useful extra in winter survival kits and cold-weather outreach supplies.