Core Heavy WoolWarm Alpine Ski Sock in Merino Wool Our warmest ski sock for alpine skiing and winter sports, knitted in a Merino Wool blend that provides superior warmth even during the coldest days. The terry knit construction throughout the entire sock provides extra insulation and comfort, while the seamless construction reduces the risk of chafing in the boot. A comfortable sock for those who want to keep their feet dry, warm and comfortable all day long.