Emergency Sleeping Bag by Grizzly Gear is made of the same Mylar material as our emergency blanket but is formed into a sleeping bag to prevent heat loss even more efficiently.This compact sleeping bag provides warmth (retains and reflects up to 90 of body heat), a waterproof and windproof shelter barrier, and a covering to help reduce shock when someone is injured. Grizzly Gear Emergency Thermal Sleeping Bag to be used as emergency shelter. Also great for camping, hiking, and surviving the cold outdoors. Excellent as liner of sleeping bag.