A key factor in the thermal protection Nomex provides is that it carbonizes and thickens when exposed to the intense heat of today's fires. This increases the protective barrier between the heat source and the skin and minimizes burn injury. This tough, protective barrier stays supple and flexible until it cools, which gives you valuable extra seconds of protection when you need it most. Garments made from Nomex are also durable, lasting on average two to three times longer than most other standard protective fabrics, including 100% cotton, polyester garment blends and typical flame retardant treated cotton.