Space blankets have many uses in emergency situations. Rescue vehicles, like ambulances and fire trucks, have started keeping them in stock to use when tending to victims of tragedy. Water crafts and agencies, like the Coast Guard, use space blankets for rescues.
Campers, hunters, and hikers are learning that space blankets are necessary parts of their gear. I the event that you get lost or stranded, a space blanket can keep you safe from hypothermia or frost bite. They also have many other ways to be used in a survival application.
In the absence of fire starting materials, a Mylar blanket can be used. Simply line a bowl with part of your blanket, fill with some flammable materials and aim the bowl to collect sunlight. Mylar blankets can also be used to collect rainwater or dew.