This page is about exactly that:
Empowering you with the knowledge and mindset to survive.
Mad Survival Gear Bivys are made with a non-laminated radiant foil sheeting. Using the Chemical Vapor Deposition (CVD) process with a polyethylene woven substrate. This engineering not only provides superior 95% thermal retention and protection from the elements the tensile and tear resistant strength provides cannibalizing options not found or capable with Mylar or any other radiant survival Bivy.
Multi-Purpose Hood
Versatile Cover Flap