Men's Midweight Thermal Base Layer Bottom. A comfortable essential done the Carhartt way. These men's thermal bottoms are made of midweight waffle knit polyester for easy-wearing warmth that wicks sweat and fights odor. These tights give you the range of motion and warmth you need when battling the cold months. 4-ounce, 100% Polyester Waffle-Knit. Midweight, Force(R) Base Layer. Built with Force FastDry(R) technology to wick sweat and dry fast. Built to move with Rugged Flex(R) stretch technology. Fights Odors. Smooth Flatlock seams, Y-split waistband, and contoured front for comfort. Strategic seam placement to reduce chafing.