What is "long underwear"?

Long underwear, also known as thermal underwear or long johns, is a type of undergarment worn to provide an extra layer of warmth during cold weather. Typically made from materials such as cotton, wool, or synthetic fabrics like polyester, long underwear covers the legs and torso, often extending down to the ankles and wrists. The snug fit helps to trap body heat close to the skin, providing insulation against the cold. Long underwear is often worn by people who work or spend a lot of time outdoors during cold weather, such as hikers, hunters, and construction workers, as well as by anyone who wants to stay warm and comfortable during the winter months. Some types of long underwear are designed to be moisture-wicking, meaning they can help to keep the skin dry and comfortable by drawing sweat away from the body.