An electric rotating machine having a stator and a rotor, wherein the rotor is provided with rotor windings connected to electric contacts to carry a field current. A control device is provided to adjust the field current carried by the rotor windings. At least one sensor is provided to give information about the temperature at the location of the at least one sensor. The at least one sensor is located on or embedded in the rotor windings, and the at least one sensor is connected to the control device such that the control device is able to read the information given by the at least one sensor. The control device is further arranged to adjust the field current carried by the rotor windings and/or power output or power input of the electric rotating machine based on the information given by the at least one sensor.