Keep your feet warm and comfortable in these Heat Holders Ladies' Size 5-9 Black Thermal Socks. These thermal socks are made from a specially developed heavy bulk yarn which has extreme thermal qualities. With long pile cushioning, these thermal socks will help keep feet fully comfortable and supported. The inside of each sock has been intensively brushed that not only feels sensationally soft but also traps warm air close to the skin keeping your feet warmer for longer.