A large thin sheet of material specially designed to keep a person warm and to prevent the further loss of body heat in an emergency rescue situation; it may additionally be intended to be used by a patient prior to surgery. It is designed as a flat whole-body wrap, blanket or poncho, and typically includes a heat-reflecting metal surface [e.g., aluminium (Al)] to help retain body heat. It is typically used by emergency medical services (EMS); it is not intended for carrying/transporting a patient [it is not a rescue bag]. This is a single-use device.