Thermal underwear, also known as long johns, are a type of undergarment designed to provide extra warmth and insulation in cold weather. They are typically made from a material that traps heat against the body, such as wool, polyester, or a blend of synthetic fibers. Thermal underwear for men often comes in a two-piece set, with a long-sleeve top and long pants, though some styles include one-piece suits.

Long johns are a popular choice for outdoor activities in cold weather, such as skiing, snowboarding, hiking, or camping. They are also commonly worn as a base layer under regular clothing to help retain body heat and keep the wearer comfortable in chilly temperatures. The snug fit of thermal underwear helps to regulate body temperature by wicking away moisture and preventing heat loss.

When choosing thermal underwear for men, it's important to consider the level of warmth needed for the specific climate or activity. Look for materials that are moisture-wicking and breathable to prevent sweating and discomfort. It's also helpful to choose a style that fits well and allows for a full range of motion. Investing in a quality set of thermal underwear can make a big difference in staying warm and comfortable in cold weather conditions. Description by ChatGPT.
