Mens Heat Holders New Twist Thermal Socks Keep feet warm during the winter freeze and put these men\'s Heat Holders on your feet the worlds warmest thermal sock. Thick bulky and with an impressive tog rating of 2.34 Heat Holders are made from a specially developed heavy duty yarn which has extreme thermal qualities. With long pile cushioning these thermal socks will keep your feet cosy warm and comfortable. The inside of each sock has been intensively brushed making them feel incredibly soft whilst trapping warmer air close to the skin allowing your feet to stay warmer for longer.