The Bogs York insulated rain boot is comfort rated to -4°F/-20°C. The 100% waterproof boot is constructed with 5mm Neo-Tech waterproof insulation and DuraFresh natural bio-technology to fight odors. It features BOGS Max-Wick lining that evaporates sweat to keep feet dry. It also features BLOOM eco-friendly, algae-based EVA footbed for comfort.