A method for determining an operating state of a PTC thermistor element may include pre-setting a released electric output available to the PTC thermistor element via a control signal and superimposing the control signal, at least for a pre-set period of time, with an additional signal which has a pre-set time profile. The method may also include, during the pre-set period of time, determining one of a time profile of a consumed electric output of the PTC thermistor element and a time profile of a consumed operating current of the PTC thermistor element. The method may also include comparing the pre-set time profile of the additional signal and the one of the time profile of the consumed electric output of the PTC thermistor element and the time profile of the consumed operating current of the PTC thermistor element.