The Sorel Glacier XT Boot wraps a removable ThermoPlus felt inner boot in Omni-Heat reflective lining, so body heat gets bounced back instead of lost to the cold. A full-grain leather upper with gore detail flexes to fit over thicker socks or a wider ankle without sacrificing the boot's waterproof protection. This winter boot is built for the days when regular footwear stops being an option. What Our Gearhead(R) Experts Are Saying:"I stood outside for a full ski-day lift line in single digits and never had to stomp my feet to keep them warm. That reflective lining does more work than I expected from something this thin."