This heavyweight RedHEAT EXTREME women's base layer zip top lives up to its name with optimal body temperature regulation. The innovative technical fabric stores and manages body heat through carbon microcrystals for maximum comfort, making it the perfect thermal base layer for people living in freezing climates. Thanks to the RedHEAT superior moisture management, our KOMBI base layer guarantees the most enjoyable experience for any winter sport. Thick and comfy, this is the best base layer for skiing.