During ice-cold shoulder season nights and après-ski parking lot hurrahs, the Outdoor Research Tundra Trax Bootie provides more protection than the average post-play footwear. These booties have all the comfort features of our favorite slippers—insulation, underfoot support, and cozy style—with added tech that feels outdoor-ready. The weather-resistant Pertex Quantum shell prevents our feet from chilling in wintry temperatures, and Primaloft insulation with Cross Core technology keeps us light on our feet while they're wrapped in trusty warmth.