An electric machine includes a plurality of conductive tracks defining an electric power circuit, to provide current for electronic power components, a printed circuit board which mounts the conductive tracks, an enclosure which defines a housing for the printed circuit board and has a dissipative wall, a heat-conductive filler interposed between the printed circuit board and the enclosure, an elastic device acting on the printed circuit board to press it against the dissipative wall, a conductive element held in position by at least one heat-sensitive joint and disposed to connect a first track and a second track to close the electric power circuit. The elastic device includes an elastic element pressed against the conductive element to apply a force on the heat-sensitive joint and the heat-sensitive joint is configured to break if subjected to a temperature higher than a predetermined threshold temperature to open the electric power circuit.