Upper limit of dynamic mean body temperature of young men trained in heat-humid environment

Abstract

Objective To determine the definitive upper limit for training with different intensities in heat-humid environment,so as to provide evidence for safe working in heat-humid environment.Methods Thirty male volunteers aged 18-23 years old who passed both health examination and physical agility test were selected from a total of 576 trainees.The body temperature,including 5-point temperatures on the skin,rectal temperature and mean body temperature calculated,were obtained before and after each training episode;the results were compared with previously reported.Then a regression equation on the mean body temperature was developed and point estimation was done subsequently.Results(1) We found that 35.83% of the subjects had a mean body temperature higher than the upper limit previously reported.(2) If ^ y was the mean body temperature,X1 was the temperature in environment,X2 was the humidity in environment,and X3 was the intensity of work,the regression equations was ^ y=14.247 68+0.604 67X1-0.018 29X2+0.343 53X3;and a table was developed according to related point estimation.(3) There were 11 person/times(2.49%) out of 441 person/times whose mean body temperature surpassed the dynamic upper limit according to the table.Conclusion The mean body temperature is related to the environment temperature,humidity and work intensity in the heat-humid environment.The table developed by point estimation of the regression equation may help to ensure safe working in heat-humid environment.