Local Heating Source for Divers

A novel method of local heating for divers has been developed. The method involves the use of a granular mixture of magnesium and iron particles packed in small sachets. Exothermic reaction proceeds when these sachets are immersed in sea water, and heating rate may be predetermined by particle size and mixture ratio of the constituent Mg and Fe particles. This method has been applied to hand heating, but further development is needed for body heating.