Abstract: An exothermic structure that is directly applied to skin comprises a pouch having an air-permeable side and an air-impermeable side, and a exothermic composition that is incorporated into the pouch in a sealed state. The air-impermeable side comprises an inner polymer sheet layer, an intermediate adhesive, and an outer release sheet, wherein the adhesive layer exists in part or entire of an outer periphery on an inner surface of the release sheet. The total area of the adhesive layer is 10 to 40% of the area of the release sheet, the adhesive layer has an adhesive portion(s) and a non-adhesive portion(s) or only an adhesive portion(s), the total area of the adhesive portion(s) is 30 to 100% of the total area of the adhesive layer, and in the outer periphery the total length of the adhesive portion(s) is 60 to 100% of the total length of the adhesive layer.