Self-heating systems and methods for rapidly heating a comestible substance

A container adapted to change the temperature of a comestible substance contained therein, comprising:

• an outer body, said outer body comprising a plurality of sidewalls which together define a recess;
• a receptacle adapted to store the comestible substance, said receptacle is disposed in the recess and coupled to the outer body to form a chamber between the receptacle and the outer body, wherein at least a portion of the chamber substantially surrounds the receptacle;
• a barrier positioned within the chamber to divide the chamber into a first and a second compartment, wherein each compartment is adapted to receive one or more chemical reactant, the barrier comprising a stationary barrier member and a movable barrier member, the stationary barrier member being substantially fixed relative to the outer body, said stationary barrier member having a fixed sized opening, said movable barrier member being removably attached to the stationary barrier member and adapted to seal the opening;
• an extension coupled between said movable barrier layer and a preselected area on the container, wherein the extension comprises at least one fin;
• wherein when a predetermined threshold force is applied to the preselected area on the container, the extension is translated so that the movable barrier member separates from the stationary barrier member in a manner such that the movable barrier member is completely detached from the stationary barrier member, resulting in the entire fixed sized opening being uncovered, thus allowing one or more chemical reactants to flow from one chamber to the other at a predictable rate, wherein pressure from the out-flowing chemical reactants pushes the movable barrier member away from the opening to substantially inhibit the movable barrier member from blocking portions of the opening;
• and
• wherein a reaction involving the chemical reactants causes the temperature of the comestible substance to change.