Made from a metallised polyester film coated on both sides, it has a heat-reflective surface which is ultra-insulating. Helping to retain most radiated body heat, whilst also protecting from the wind and rain, this helps to treat and prevent hypothermia after first aid has been administered. For example, these are given to marathon runner after the finish line to help them regulate their body temperature as this drops rapidly when they stop working their muscles. Strong and waterproof, foil blankets are ideal for emergency situations and should be added to all first aid kits which do not already contain them. Its size is 1.4m by 2.04m, so is perfect for wrapping around the body, but fold down into a compact size.