Package heating device and chemical compositions for use therewith

A heating device comprising:

• a heating chamber defining an interior space for receiving and storing a substance to be heated;
• a pocket adjacent to the heating chamber for receiving a modular heater;
• and
• a modular heater comprising a housing comprising a canister portion and a lid portion sealed together and defining an exterior shape of the heater and a sealed interior space, wherein the lid portion is flexible,
• the modular heater further comprising a solid state chemical heating composition and an activation mechanism disposed within the sealed interior space, the modular heater disposed within the pocket;
• wherein the actuation of activation mechanism generates sufficient thermal energy to initiate a chemical reaction of the solid state chemical heating composition, wherein the activation mechanism is disposed adjacent to the lid portion and is actuable by flexing the lid portion, and wherein the activation mechanism comprises a piston, a blister pouch containing a first reaction initiation material, and a pellet comprising a second reaction initiation material and in communication with the solid state chemical heating composition, wherein the pellet further contains fibrous particulates to promote wicking and rapid absorption of first reaction initiation material;
• the piston, blister pouch and pellet being arranged within the heater such that when the lid portion is depressed, the piston is depressed and ruptures the blister pouch, thereby allowing a first reaction initiation material to contact the pellet and initiate a chemical reaction between the first reaction initiation material and a second reaction initiation material that generates sufficient thermal energy to initiate reaction of the solid state chemical heating composition.