What Our Gearhead(R) Experts Are Saying:"This pack is a must for skiing and snowboarding. It fits snugly under my jacket to keep the water from freezing, and the slim design is comfortable for all-day wear. The Crux reservoir's ergonomic design makes refilling easy, even with gloves on."For cold-weather pursuits, the CamelBak Bootlegger Hydration Pack delivers hydration in stealth mode. With its slim, low-profile design, it fits comfortably under a ski or snowboard jacket, keeping the 1. 5L Crux reservoir insulated and freeze-free. We appreciate how its dual sternum straps ensure a secure fit, even when carving through powder or tackling technical runs. The Bootlegger is designed to handle sub-zero temperatures, thanks to an insulated tube and reservoir compartment that protect our water supply. It's a simple, efficient solution for staying hydrated during frosty adventures without compromising comfort or mobility.