The thermal material (50) comprises a heating element (10) having a heat generating portion (10) containing a metal oxide, carbon component and water, a housing (20) having a partially ventilating portion and accommodating the heat generating portion (10) therein, and a cooling agent is held in the hot metal (50), and satisfies the following conditions.(condition)Under the environment ofThe amount of the devolatilization of the quenching agent per 30 minutes after the start of the heat generation of the heating element (100) is 0.01 mg or more and 0.3 mg or less.The ratio of the accumulated vapor amount (mg) measured from the start of the exothermic reaction of the heating element (100) to the increase temperature (. Degree. C.) of the surface maximum temperature of the thermal material (50) after the start of the exothermic reaction of the heating element (100) to 10 minutes after the start of the heat generation is 10 (mg / ° C.) or more.Diagram温熱具（５０）は、被酸化性金属、炭素成分及び水を含有する発熱部（１０）と、一部に通気性を有し、発熱部（１０）を内部に収容する収容体（２０）と、を有する発熱体（１００）を備え、温熱具（５０）に清涼化剤が保持され、以下の条件を満たす。（条件） ３０℃の環境下において、 発熱体（１００）の発熱開始後３０分あたりの前記清涼化剤の揮散量が、０．０１ｍｇ以上、０．３ｍｇ以下であり、 発熱体（１００）の発熱開始から発熱開始１０分後における温熱具（５０）の表面最高温度の上昇温度（℃）に対する、発熱体（１００）の発熱開始から発熱開始後１０分までに測定される積算蒸気量（ｍｇ）の比が、５（ｍｇ／℃）以上である。【選択図】図１
