The thermal fuse is integrated in the capacitor core and responds to overtemperatures caused by electrical or thermal overload. The fuse element within the body melts when a critical temperature is reached. It melts into small open globules which are completely insulated from each other not only by the distance but also by a special insulating compound which appears at the point of meltdown. The thermal disconnection is resistant to surge currents within the permitted range of capacitor current.