Boot Glove Directory - A simple concept is followed. The inner liner of your boots keep your feet warm. The problem is the outer liner has little insulation and when it gets cold, it over takes the warmth away from the inner liner. That's when your feet get cold. So, if you keep the outer liner warm, your feet will stay warmer. Boot Glove keeps the shell of the boot away from the cold and keeps your feet warm by using materials of heat trapping Neoprene and Velcro that blocks cold, wind and snow chill. The BootGlove has been tested to keep the shell of the ski boot as much as +50 degrees warmer.