An enclosing member including a sheet member connected in a liquid tight manner, refrigerant enclosed in the enclosing member, and an absorbing member arranged in the enclosing member and absorbing the refrigerant. The enclosing member includes a condensation section where the refrigerant that is in a gaseous state is condensed, and in the condensation section, the absorbing member is attached on at least a lower section of an inner surface of the enclosing member with respect to a vertical direction.