The Sympatex membrane is laminated into the inside of the first heat shield. This ensures that rain, moisture and heat are kept outside, whilst perspiration is still able to escape. Sympatex is a 'breathing' material: it is watertight and wind-proof, protects against bacteria and viruses and is resistant to chemicals and heat. As moisture barrier and insulation layer, Vilene Fireblocker heat shield with  Sympatex membrane lowers the possibility of heat stress.