Thermal sensation of the body as influenced by the thermal microclimate in a face mask.
Nielsen-R; Berglund-LG; Gwosdow-AR; DuBois-AB
Ergonomics 1987 Dec; 30(12):1689-1703
The significance of the thermal microclimate over the face for the whole body thermal sensation during exercise at different ambient temperatures was evaluated in subjects wearing face masks. Stimuli included several combinations of air temperature and humidity inside the mask. Heart rate and skin temperature and wettedness were measured while subjects exercised for 15 minutes on a bicycle ergometer. No effect on heart rate was detected as a result of changing ambient air temperature or mask air temperature. The mean heart rate over minute 11 to minute 15 of the test averaged 112 beats per minute. No change was noted in the subjects' mean skin temperature over the course of any particular condition. Mean skin temperature was a linear function of the ambient temperature, as were all local skin temperatures, except for the skin temperature in the area of the mask itself. Significant increases were noted in skin wettedness under the clothing as the test proceeded from the exercise period in the neutral (16 degrees-C) to the warm (25 degrees-C) environment. Only a small increase in skin wettedness was noted when exercise was conducted in the cold environment (7 degrees-C). The higher ambient temperatures and the higher mask air temperatures produced higher ratings of whole body thermal sensation. No detectable effect on whole body thermal sensation resulted from humidity changes in the mask. The sensation of skin wettedness and sweating on the whole body surface was significantly enhanced by both an increase in the ambient air temperature and an increase in the mask air temperature. Both ambient and mask air temperature increased the sensation of sweating and skin wettedness in the mask area. The authors conclude that mean body temperature is not always the determinant of whole body thermal sensation. The influence of increased neural input from the face area compared to other skin areas to the brain centers should be considered.
NIOSH-Publication; NIOSH-Grant; Respirators; Thermal-effects; Body-temperature; Thermoregulation; Humans; Face-masks; Temperature-regulation; Laboratory-testing; Cold-environments; Hot-environments; Physiological-response; Cardiovascular-system
None John B Pierce Foundation, Inc 290 Congress Avenue New Haven, Conn 06519
John B. Pierce Foundation Lab, Inc., New Haven, Connecticut