PURPOSE: To extend sharply cold insulation time in which a good feeling touch an be felt by separating two hydrate bags, forcibly breaking and opening a first hydrate bag, pushing down a pushing rod, which is an opening rod, then opening a second hydrate bag after a specified time, and mixing a hydrate agent with an endothermic agent so as to cause endothermic reaction.

CONSTITUTION: A cold heat material pack 11 comprises two hydrate bags, say, a first hydrate bag 12A and a second hydrate bag 12B, an endothermic bag 15, and an outer covering layer 16 which contains a polymeric endothermic agent 18 covering the outer sides of the endothermic bag 15 and the hydrate bags 12. When the hydrate bag 12A is broken open with a pushing rod 21, an endothermic agent 17 in the endothermic bag 12A is mixed with an endothermic agent 13 in the endothermic bag 15, thereby causing endothermic reaction and lowering the temperature in the endothemric bag 15 as well. The moisture separated by the endothermic reaction is absorbed into a polymeric hydrate agent 14, turned into gel state so that a good feeling touch may be provided to the skin in contact with the outer covering layer 16 placed on the outside of the endothermic bag 15. Dew drops and human sweat outside the hydrate bags and the endothermic bag are also absorbed into a polymeric water absorption agent 18. Then, the hydrate agent 17 in the hydrate bag 12B is mixed with an endothermic agent 13 in the endothermic bag 15, thereby causing endothermic reaction, and lowering the temperature in the endothermic bag 15 again. It is, therefore, possible to extend cold insulation time which provides a good feeling touch.