Abstract: A trigger to activate a supercoolable aqueous salt solution wherein the trigger and solution are encased within a flexible container. The trigger is a flexible relatively thin sheet of material wherein there are a plurality of activator cuts that extend through the thin sheet material and the shape of each slit includes a first or central slit and a minor slit that extends through the thin sheet material at one end of said first slit and at an angle to the direction of the major slit. In addition the method of making the trigger is accomplished by punching, forming, dishing and cutting the end product to its exterior dimension.