Men's HEATR® Tundra Base Layer Bottom 953HBPB Made in USA WSIWarmWill keep you warm even in temperatures from 0 to 75 F Contoured Fit Base layer for minimal bulk and moderate warmth HEATR is located throughout the entire shirt for enhanced thermal warmth Flat inner seams for added comfort Care Instructions: Machine wash cold, gentle cycle, with like colors Line Dry HEATR: 70% Polyester, 27% HEATR, 3% Spandex HEATR is a high tech material developed by WSI that helps keep you up to 40% warmer than other materials on