Elevation of Nasal Mucosal Temperature Increases the Ability of the Nose to Warm and Humidify Air

Abstract

The nose functions to warm and humidify inspired air. The factors that influence these functions have been studied to a limited degree. We have developed a method for measuring the temperature and relative humidity of the air before and after nasal conditioning to study nasal function. In this experiment we studied the effects of raising the mucosal surface temperature by immersion of the feet in warm water. Six subjects (avg. age = 27.0 years) were randomized to immersion of the feet in 30°C and 40°C water. The nasal mucosal temperature increased significantly from the 32.2 ± 1.3°C during immersion in the 30°C water to the 33.1 ± 1.2°C during immersion in 40° water (p < 0.05). No significant difference in nasal volume was noted between the 30° (17.8 ± 4.5 cc) and the 40° (17.7 ± 5.3 cc) immersions. There was a significant increase in the conditioning capacity of the nose (as measured by total water content of inspired air) in response to cold-air challenge during the 40° immersion (1669 ± 312 mg water) when compared to the 30° immersion (1324 ± 152 mg water). From these data we deduce that warming of the nasal mucosa improves the ability of the nose to condition inspired air without a significant change in the volume of the nasal cavity.