Abstract: Wearable thermoelectric generators (w-TEGs) rely on heat transfer between the human body and the surrounding environment to produce electrical power. Their performance depends strongly on how heat flows through the contact area between the skin and w-TEGs, through the thermoelectric legs, and toward the surrounding environment. This presentation provides an overview of the heat transfer processes that influence the operation of w-TEGs, including conduction within the device layers, convection at the external surfaces, and radiation exchange with the environment. The discussion highlights how these mechanisms affect the temperature differences available during real use and, consequently, the electrical output. The aim is to provide a clear perspective on the heat transfer processes that affect w-TEG performance and to outline approaches to improve their performance across different applications.