Abstract: An electronic human body temperture indicator comprising a thermocouple, the hot junction of which is housed within a tube through which the patient's breath is exhaled. The cold junction is positioned in contact with the ambient air, and an adjacent ambient temperature air sensor is provided. An appropriate electronic package processes thermocouple and air temperature sensor output to provide a display of the patient's peak breath temperature. A breath outlet check valve prevents cross contamination by blocking inhalation through the indicator. A disposable breath inlet tube makes sterilization unnecessary between uses from patient to patient. According to one aspect of the invention, the indicator may be adapted for anesthesiology use, the hot junction then being located in an elbow connecting the gas supply tube and the disposable treachea tube.