Heat pack and trigger apparatus

Claim 1

In a flexible heat pack package containing a supercooled salt solution, the improvement comprising a flexible packet at least partially contained within the heat pack package and exposed to the salt solution contained therein, a trigger contained within said flexible packet, said trigger including a substantially elongated planar body portion having opposite first and second ends, said first end defining means for piercing said flexible packet, said second end defining a blunt surface for engagement by a force-producing instrumentality, said force being directable generally along a plane of said body portion in a direction toward said first end, and wherein said means for piercing said flexible packet defined by said first end of said trigger is of a geometry which is substantially incapable of piercing said flexible package at a location on said flexible package other than a side seam thereof, a chemical moiety capable of activating crystallation of said supercooled salt solution contained in said heat pack package carried by at least said first end of said trigger, whereby upon the application of said force to said second end of said trigger, said first end is caused to penetrate said flexible packet and enter said heat pack package and introduce said chemical moiety to said supercooled salt solution and effect crystallization of said salt solution with resultant production of heat.