Mylar Foil Rescue Blanket The Mylar Emergency blankets are designed to reflect heat back to body, or deflect heat when used as a shelter from the sun. Prevents post accident shock by retaining the patients body heat. Product Features: Compact emergency protection. Lightweight packaging. Durable Mylar insulation material. Retains & Reflects body heat. Waterproof & Weatherproof. Dimensions: 62 x 82.