Warmth Rating Earned: Level 3 - Warmest Engineered For High Warmth in Severely Cold Conditions. See Technology section below for more details. Engineered For high warmth in severely cold conditions, anyone who works outside can appreciate the cold-weather chops of this men's flannel-lined hooded jacket. It's crafted with rugged cotton duck, and the body and hood are lined with quilted flannel for under-the-covers warmth. A rib-knit waist and cuffs keep heat in, cold out, and prevent excess material from getting in the way of your work.