The sleeping bag is made of aluminum foil. It has a metal coating on the surface.
The inner layer is a PE plastic film, which can reflect the heat back to the body in order to keep you warm.
The emergency sleeping bag is used in special circumstances like earthquakes or outdoor distress.
This emergency sleeping bag can still keep away you from cold, which is very useful and convenient.
This bag is not a one-time-use bag. After each use, you should carefully fold it in order to use it again.