When organizing my Kilimanjaro hike, I was obsessed by one major concern: How to keep warm feet (or rather how to avoid frostbite) during summit night? Fear turned into excitement when I learned about chili-feet from a real outdoors expert. According to him and all my further research, they are the warmest insoles currently in the market. In essence, their innovative material produces heat purely from the pressure of walking. How wonderful would that be: Just put them into your shoes and no more cold feet when walking in winter!