The fabric in this new thermal bottom, which is 30% heavier than most other thermals, means youÆll stay warm no matter how long you remain outside to finish the job. Made from premium, 9.5-ounce cotton, this knit features a double elastic waist that provides great ease of movement, flat-lock stitched seams for durability, and low shrinkage for a more consistent fit. The heavyweight fabric traps body heat in for warmth, and the comfortable rib-knit leg openings ensure that cold air is locked out. This job-tested thermal is hard working, rugged and all Carhartt.