FIELD: mining.SUBSTANCE: heat source comprises a body, which is equipped with a composite material that generates gas during combustion and actuates from an electric spiral, and layers of epoxide compound and thiocol-based sealant sealing the ends of the material of the gas-generating composition. The composite material of the heat source that generates gas during combustion contains efficient amount 20 wt % of powdery polyvinyl chloride chlorinated resin of brand PSH-LS at the following ratio o...