What is a "ski mask"?

A ski mask is a type of headgear that covers the entire face except for the eyes, nose, and mouth. It is typically made of a warm, breathable fabric such as fleece, wool, or synthetic materials. Ski masks are commonly worn during outdoor winter activities such as skiing, snowboarding, and snowmobiling to protect the face and head from cold weather conditions. Some ski masks come with additional features such as ventilation, moisture-wicking technology, and anti-fog lenses for the eye area. They are also often used as a disguise in movies, TV shows, and other forms of entertainment.