Many factors contribute to cold feet. Heat loss through the bottom of your shoe when standing on outdoor or indoor surfaces cooler than your body temperature is one significant cause.
Toasty Feet retain their insulating qualities over time because they won't compress or crush (reducing loft).
Toasty Feet also keep your feet cooler while walking on hot surfaces. They're great for anyone during the hot summer months and a must have for people where heat can become excessive.