A solid state thermite reaction composition is provided comprising a fuel component, an initiating oxidizer, a primary oxidizer, a fluxing agent and a thermal diluent. According to another aspect, a heating device is provided comprising a heating chamber for receiving and storing a substance to be heated having at least two walls, a reaction chamber affixed to a wall of the heating chamber, a solid state thermite reaction composition located within the reaction chamber and an actuatable trigger mechanism affixed to the reaction chamber such that the trigger mechanism is in contact with the reaction composition. According to another aspect, a solid-state thermite reaction activation mechanism is provided comprising a first compound substantially in contact with a thermite reaction fuel, a second compound and a removable barrier located between the first and second compounds preventing any contact between the first and second compounds.