The Brand New Xtreme Heat Men's Black Thermal Shirt & Pants Set in size Medium is a base layer set designed for outdoor activities in cold weather. Made from a blend of polyester and cotton, the knit fabric provides warmth and mild compression for the body. The long sleeve shirt and pants feature a stretch accent for added flexibility. Ideal for hunting, outdoor adventures, or winter sports, this thermal set from Xtreme Heat is perfect for keeping you comfortable and cozy in chilly conditions.