Great for taking along on a trip or storing in your car, the Heat Factory Hand and Body Warmers can be inserted into pockets, stadium cushions, sleeping bags and other Heat Factory accessories. Heat Factory’s Large Size Warmers provide instant, long-lasting heat for outdoor activities in the cold. Each warmer is non-toxic, odorless and provides up to 20 hours of reliable, even heat. The Heat Factory Large Body Warmer is a soft, lightweight pouch containing a mixture of iron powder, charcoal, salt and vermiculite. When exposed to the air, an oxidation process takes place that generates heat. Heat Factory warmers are specially engineered to provide quality heat that is long-lasting, comfortable, and even. Heat Factory continually tests its products to ensure that you receive only the highest quality warmers that will consistently deliver warmth as advertised. Once activated, Heat Factory warmers can even be saved for later use (preferably within a week) if placed in an airtight container. Unopened, the Heat Factory warmer has a shelf life of three years or more. Proudly designed and hand-made in the USA, Heat Factory’s air activated hand warmers, body warmers, toe warmers, and heated accessories have been providing warmth and pain relief to outdoor enthusiasts for the past 30 years.