The invention relates to a device for measuring the temperature in the anus or in the vagina of an animal, wherein a front longitudinal part, an abutment part and a rear longitudinal part lie in succession on the device, wherein the front longitudinal part is equipped with a temperature sensor and, when used as intended, it is intended to be inserted into the anus or the vagina of the animal until the abutment part approximately rests against the outside of the body of the animal. One or more further temperature sensors are attached to the rear longitudinal part and/or to the abutment part, which, when used as intended, are provided for measuring the temperature in the surroundings of the animal.

A temperature measurement device, comprising a spectral measurement system, configured to determine the absorbance of tissue at a plurality of frequencies, and an analysis system, configured to determine the temperature of the tissue from the determined absorbance, wherein water has a temperature dependent absorption at one of the plurality of frequencies that is different than that at another of the plurality of frequencies.