When the temperature outside is so brutal that your pee crystallizes before it hits the ground, the time has come to bust out your Outdoor Research Alti Mitten and its Gore-Tex shell. Constructed for high-alpine mountaineering, arctic expeditions, and other pursuits into the frigid kryosphere, the Alti Mitten blends waterproof Gore-Tex membrane with a removable PrimaLoft-insulated liner to provide digit-saving protection from the ungodly cold elements.