Definition
Long johns are a type of thermal underwear consisting of a one-piece garment with long sleeves and legs, designed to provide warmth in cold weather. Think of them as a full-body hug on a chilly day. They are typically made of cotton, wool, or synthetic fabrics like merino wool, known for their insulation properties. They are worn as a base layer under clothing to trap heat and wick away moisture. They are popular for outdoor activities like skiing, snowboarding, and hiking in cold climates. They can also be called thermal underwear or base layers. Staying warm is the name of the game.