Do not hesitate to unwrap your Mylar bag and snuggle inside. The longer you wait to decide that you are indeed in an emergency situation worthy of breaking out the life-saving gear, the more body heat you lose. If possible, hug another person, or even your dog, and wrap yourselves inside one or two emergency thermal blankets to increase the heat exuding from inside the bag. Mylar blankets are extremely flimsy and the ends are known to move about in even a slight breeze. Tuck the ends as tightly as possible, and do not forget to cover your head. Some people even recommend using the emergency thermal blanket poncho style after removing your jacket and putting it back on outside of the bag. Mylar is not a breathable material, so be mindful of moisture buildup. It is best to remain both warm and dry, and not damp.
Click here to read the rest of my Mylar blankets uses report on Off The Grid News and learn all the ways the tiny, lightweight survival gear packets could help save your life.