Provide a heating element that can be worn on the body. The heating element is provided with a bag body formed by overlapping two sheets and joining the outer periphery thereof over the entire circumference； the heat generating material enclosed in the bag body； and a cover provided on the second sheet side of the bag body, the cover The cover is provided by forming a space capable of inserting a part of the body between the cover and the cover. The cover is non-breathable.提供能著裝於身體上的發熱件。發熱件具備有將2枚片材重疊並將其外周緣遍及全周接合而形成的袋體；封入在袋體的發熱材料；以及設置在袋體的第2片材側的蓋套，前述蓋套是藉由在與袋體之間形成能夠將身體的一部分插入的空間的方式來設置，蓋套為非透氣性。
