The Heat Holders Men's ORIGINAL Dunnock Twist Crew Sock delivers serious warmth with understated style - 7x warmer than a standard cotton sock. These socks are crafted with advanced thermal yarns and an intensely brushed inner lining, helping maximize the warm air held close to your feet for lasting comfort in very cold conditions. The subtly textured twist knit keeps feet warm, dry, and comfortable from dawn to dusk.