Abstract: In a thermal pack, one which may be provided with ingredients for making it either a cold pack or a hot pack, three bags are provided for the container of the pack, two of said bags being of the same size and comprising the exterior and proximate interior liners of the pack, while another bag of lesser dimensions forms the inner liner of said pack, and is disposed within the two larger bags. The inner bag is designed for holding a quantity of water, while the interior liner of the two outer bags is provided for holding a quantity of chemical means for use in varying the temperature of the desired type pack. Rupturing of the inner bag through manual pressure allows water to react with the chemical means for creating either the cold or hot temperature, as needed.

Abstract: In a thermal pack, one which may be provided with ingredients for making it either a cold pack or a hot pack, three bags are provided for the container of the pack, two of said bags being of the same size and comprising the exterior and proximate interior liners of the pack, while another bag of lesser dimensions forms the inner liner of said pack, and is disposed within the two larger bags. The inner bag is designed for holding a quantity of water, while the interior liner of the two outer bags is provided for holding a quantity of chemical means for use in varying the temmperature of the desired type pack. Rupturing of the inner bag through manual pressure allows water to react with the chemical means for creating either the cold or hot temperature, as needed.