Keep feet warm on the coldest of days with Heat Lockers® thermal socks! Heat Lockers® special 3-stage construction keeps feet up to 7X warmer than a basic cotton sock and 3x warmer than an ordinary thermal sock: 1 - Heat Locker yarn™ is specifically designed for its thermal insulation and soft touch properties. 2 - Heat Locker loops™ have been developed to create a thicker pile that locks more warm air next to your feet. 3 - Heat Locker inner™ has been carefully brushed to further enhance warmth and comfort. Heat Lockers® are non-binding. They are diabetic friendly and provide relief for cold feet due to circulation problems.