An overheating protection system for a control unit includes an interrupter element, which, in its initial position defined with respect to a circuit board, electrically connects the opposite facing ends of at least one track on the circuit board, and an actuating element which is activated with the overheating of the transistor, and which on actuation against the interrupter element takes effect and releases it at least so far from the tract that the electrical connection is interrupted. A preassembled actuating unit for the interrupter element of the overheating protection is comprises an accommodation housing, in which an actuating element is accommodated and which can be brought into interaction with the interrupter element and which is held releasably by a one-piece latching element formed on the accommodation housing under pretension. An electrical heating device with a control unit protected against overheating is also provided.