Abstract: An apparatus for ascertaining and/or monitoring at least one temperature. The apparatus includes, according to a first variable, at least one temperature sensor, at least one reference temperature sensor, and at least one heating/cooling unit, which is thermally coupled with the temperature sensor and with the reference temperature sensor. According to a second variant, the invention includes that at least one reference temperature sensor, and the temperature sensor and the reference temperature sensor are embodied and placed in such a manner that they measure essentially the same temperature. At least one head transmitter is provided, which connects the temperature sensor and the reference temperature sensor with the head transmitter in such a manner that the head transmitter receives the data measured by the temperature sensor and the reference temperature sensor. At least one memory unit is provided, in which the measured data of the temperature sensor and the reference temperature sensor are storable.