Space blankets, also known as emergency blankets or mylar blankets, are lightweight, thin sheets made from a metallic plastic called Mylar. They are designed to reflect body heat, making them useful in emergency situations to prevent hypothermia. Originally developed by NASA for use in space missions, space blankets are now commonly used in outdoor activities, first aid kits, and survival gear. Their compact size and low weight make them easy to carry, while their reflective surface helps retain warmth in cold conditions.