A compact electric motor (1) includes a housing (2), a stator (3), a rotor (4) with a rotor winding (5) or permanent magnets located thereon. A thermal protection device protects the electric motor against overheating. A sensor unit (6) is provided as a thermal protection device. The sensor unit (6) includes a temperature sensor (7) for detecting temperature-based measurement values, a radio module (8) with an antenna (8a) for sending sensor signals of temperature-based measurement values or data or information derived therefrom by radio to an external receiving unit (9). The sensor unit (6) has a memory (13) and a microcontroller (10). The sensor unit (6) is a self-supplying assembly.