Thermoregulation in humans of different ages during thermal transients.
Gonzalez-RR; Berglund-LG; Stolwijk-JA
Contributions to Thermal Physiology: Satellite Symposium of the 28th International Congress of Physiological Sciences, Pécs, Hungary 1980. Székely M, Szelényi Z, eds., Elmsford, NY: Pergamon Press, 1981 Jan; :357-361
Healthy men and women participated in a study of thermoregulatory responses made during carefully timed increases and decreases in ambient temperature and dew point temperature. The 40 subjects ranged in age from 8 to 67 years. Each subject was exposed in a semireclined position to an initial period of 30 minutes at 30 degrees-C, after which time the chamber temperature was increased at the rate of 1.5 degrees/minute for 20 minutes, leveling off at 50 degrees. Following a 30 minute hot and dry exposure, the dew point temperature was raised to 30 degrees and responses were monitored for another 25 minutes. After this time the chamber temperature was lowered, falling rapidly and leveling off at 9 to 10 degrees where it remained for 40 to 60 minutes. Measurements were made of esophageal temperature, heart rate, chest sweating, local skin conductances, and rate of body weight loss (due to sweating). The study demonstrated the usefulness of thermal transients in revealing quantitative differences in thermoregulatory responses among individuals. For the group in this study, the thermoregulatory heat loss responses were more strongly determined by maximum aerobic capacity as a possible consequence of the close linkage between physical fitness, evaporative heat loss and deep body temperatures. For heat production responses during cold transients, it was noted that sex and age have a more complex role in modifying thermoregulation as a multiplicative type of control.
NIOSH-Grant; Grants-other; Thermoregulation; Thermal-effects; Temperature-effects; Temperature-regulation; Physiological-response; Heart-rate; Sex-factors; Age-factors
None John B Pierce Fdn Laboratory 290 Congress Avenue New Haven, Conn 06519
Other Occupational Concerns; Grants-other
Contributions to Thermal Physiology: Satellite Symposium of the 28th International Congress of Physiological Sciences, Pécs, Hungary 1980
John B. Pierce Foundation Lab, Inc., New Haven, Connecticut