Heat Holders - Kids Winter Warm Thermal Socks 91% Acrylic, 5% Nylon, 3% Polyester, 1% Elastane Machine Washable Kids Heat Holders - Having cold feet is horrible no matter what your age you are. These Childrens Heat Holders mean that they will no longer have cold feet. Advanced Insulating Yarn - Our specially developed advanced fibres provide high performance insulation against cold with superior moisture wicking abilities. Long Looped Thermal Pile - Innovative knitting technology produces our unique, extra long looped pile to hold in more warm air, increasing the thermal tog rating. Soft Brushed Inner - Finally, an intense brushing process maximises the amount of warm air held inside the sock for all-day warmth and comfort Over 7x Warmer than a basic cotton sock - A basic cotton sock is usually tog rated at 0.33 tog, whilst a normal thermal sock usually tog rates at 0.89