Mylar, Reflective, Bivy Bag, Bivy Sack Imported Loss of body heat is the leading cause of death in emergencies. The Emergency Survival Mylar Thermal Sleeping Bag can improve your chances of survival in all weathers, seasons and environments. It is made of durable thermal insulation Mylar material designed by NASA for space exploration. It absorbs/reflects body heat. It is reusable, waterproof and windproof. The Emergency Survival Mylar Thermal Sleeping Bag is oversized, 84 inches long and 36 inches wide. The edges are decorated with bright black stripes for increased visibility. It is mainly used as an emergency shelter, but also great for camping, hiking and outdoor cold weather protection. The Emergency Survival Mylar Thermal Sleeping Bag contains two packs. Each pack comes with a separate carry bag with drawstring. Each pack weighs only 2.8 ounces (3.0 ounces with carry bag). Each pack measures 7 inches x 3 inches. It is very lightweight and easy to carry and store in your car, backpack or emergency bag. The upgraded hood is up to 21 inches wide. The bivy bag can fully cover the head. The emergency sleeping bag can effectively keep the whole body warm! The 120 decibel whistle can send a distress signal in an emergency. For customers who have never bought a warm sleeping bag or blanket, it is important to know that the material is very thin. It is designed for space exploration. Therefore, even if the sleeping bag or blanket is large, they can be folded into a very small size.