A shape of the oral temperature probe is sculptured to facilitate its self-guidance toward the root of the tongue. The probe body consists of two distinct sections—the stem and curved elbow. The stem carries a contact temperature sensing tip. The elbow allows the probe to go around the teeth of the lower jaw and position the stem under the tongue in order to direct the temperature sensing tip toward the root of the tongue. To speed up the probe temperature response, before inserting the probe into a mouth, the probe tip is preheated to a temperature that is cooler than the lowest expected temperature of the patient.