The core function of a windproof and cold-proof mask is to provide warmth for the mouth, nose and the surrounding area of the face in winter, while blocking the direct blow of cold wind and reducing the irritation of cold air to the respiratory tract and skin. It is a practical protective gear for going out in low-temperature weather. Its specific functions focus on three aspects: 1. It retains warmth by covering the mouth, nose, cheeks and other parts to form a local warm space, preventing frostbite caused by cold air directly contacting the skin and reducing the loss of exhaled hot air to maintain the temperature of the respiratory tract. 2. It provides windproof protection. Most masks are made of windproof fabrics (such as nylon and composite cloth), which can block the infiltration of cold wind and avoid discomfort caused by "cold wind choking the nose", making them especially suitable for scenarios like windy days, cycling and commuting. 3. It offers basic filtration, which can block some dust and droplets, reduce direct irritation of external pollutants to the respiratory tract, and achieve both warmth retention and basic protection.