This Mylar Emergency Survival Blanket is ideal for extreme cold survival situations because the Mylar foil reflects 90 percent of your body heat back to you. Mylar foil assists the body in heat retention during emergency situations. Emergency blankets are individually bagged. Perfect for emergency protection in all weather conditions. Waterproof and windproof. Will not crack or shrink. It is reusable and can also be used as Shelter, Ground Cover, etc... Great for Camping, Hiking, Emergency Kits and Outdoor Activities.