Exothermic body and method for manufacturing exothermic body

Provided is an exothermic body capable of following extensions and twists in a plurality of directions of a body and having a good sense of fit, and also provided is a method for manufacturing the exothermic body. The exothermic body includes an adhesive portion in the lateral direction of an exothermic portion and is characterized in that: a linear cut is provided between the exothermic portion and the adhesive portion, the linear cut being tilted with reference to a front-rear direction of the adhesive portion; and at least one end of the linear cut is bent. This enables the exothermic body, even when being attached to each part of a body or the like, to follow motions including extensions and twists in a plurality of directions, thereby preventing the exothermic body from dropping. Since the exothermic body can extend in the plurality of directions, there is no sense of discomfort, such as being pulled in a specific direction, when the exothermic body is attached, so that a good sense of fit to body movements can be obtained. In addition, the inner periphery surface of a portion formed when the cut is widened becomes a curved shape, so that there is no sense of discomfort even if the exothermic body contacts the skin.