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Hot air breathing: effects of elevated wet bulb temperatures on tissue temperatures of the mouth.
Gallagher S; Vercruyssen M; Deno NS
Am Ind Hyg Assoc J 1985 Jun; 46(6):332-335
The effects of breathing hot, humid air on the tissue temperature of the tongue and hard palate were studied in six healthy volunteers, aged 21 to 28. Temperatures were taken by means of thermocouples. Wet bulb temperatures during the hot, humid air inhalation sessions ranged from 34.7 to 49.3 degrees-C. Volunteers were subjected to a different wet bulb temperature each day in random order while performing a 60 minute treadmill operation which elicited a work rate of 40 percent of each subjects' aerobic capacity. At minute 45, each subject was asked to subjectively evaluate discomfort. All data was analyzed using a univariate analysis of variance of repeated measures statistical technique. Changes in tongue and palate temperatures were dependent upon the wet bulb temperature of inspired air. As the wet bulb temperature increased, tissue temperatures also increased. The correlations of tongue and palate temperature to inspired wet bulb temperature were both 0.973. Core temperature and heart rate were not affected by inhalation of air with elevated wet bulb temperatures. Ratings of subjective discomfort increased proportionately with increases in wet bulb temperature of inspired air. Discomfort was often first felt in the gums. The authors suggest that standards for maximum permissible temperatures of inspired air for rescue respirators and similar self contained breathing apparatus be established with regard to the inspired wet bulb temperature of the air.
Humidity; Breathing; Air-monitoring; Air-temperature; Medical-research; Humans; Physical-stress; Heat-exposure; Physiological-measurements; Physiological-response; Temperature-effects; Temperature-regulation; Physical-exercise; Exposure-limits; Emergency-equipment
Issue of Publication
American Industrial Hygiene Association Journal
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division