The ReadyHeat blanket utilized proprietary technology and all natural ingredients to deliver continuous and consistent warming. This product is part of US military protocol and carried by every US Army Medic. It can be used as an evacuation litter in an emergency situation, as it can hold a patient up to 250 lb. As an individual unit, The Ready Heat Blanket's self-heating, 4-cell liner provides 10 hours of continuous dry heat up to 125°F (52°C). WARNING: DO NOT PLACE DIRECTLY ON EXPOSED SKIN.