These heating socks are the ultimate solution for cold feet. Our over-the-calf socks benefit from the KOMBI WARM-UP adjustable heating technology powered by a USB battery pack that lasts up to 8 hours. Extra support on the arch and ankle, as well as heel and toe reinforcement provide maximum warmth and durability. The integral medium cushioning allows for comfort without adding bulk, while the toe cap heating element ensures your feet stay completely warm. With 25% merino wool, naturally antimicrobial and 3 levels of heat, these are the best heated socks for winter activities in very cold conditions, like cross-country skiing and alpine touring. Plus, with a 2-year warranty, these KOMBI socks will keep you warm for seasons to come.