This emergency survival sleeping bag is made from the same reflective foil the emergency blankets are made from and protects against wind and rain. It prevents the loss of a large percentage of body heat and is essential when trying to keep warm, or when trying to keep an injured person warm. The space bag is perhaps a better option than the blanket as a person can climb into it like a sleeping bag and will get better protection. Every kit should have one of these for each person.