Temperature profile in the nasal cavity.

Inspired air is heated and moistened as it passes the nasal cavity. The temperature increase should be similar to a heated tube model, depending on the airflow. Intranasal temperature values of 50 volunteers were measured after inspiration at different locations: nasal vestibule, nasal valve area, anterior to the head of the middle turbinate, and the nasopharynx. Temperature values were related to nasal airway resistance data. Intranasal temperature measurements were made with a miniaturized thermocouple. Nasal airway resistance was detected by active anterior rhinomanometry. A logarithmic increase of air temperature from the anterior segment of the nose to the posterior part was noted. In the nasopharynx temperature was approximately 34 degrees C. The highest increase in temperature was observed in the nasal valve area. The temperature increase of ambient air in the nasal airways can be compared with a logarithmic curve of the heating of air passing a heated tube. As the heating of air is important for water transport, the space between the nasal valve and the middle turbinate is of special functional importance. No correlation to the results of rhinomanometry was found.