Experiment Study On Heat Acclimatization And Its Influencing Factors In Hot And Humid Environments

With the rapid development of economy and technology,hot and humid environments are prevalent in various workplaces.When working in these environments,human are at considerable risk for experiencing changes in a variety of physiological parameters,such as increases in the heart rate,body temperature and blood pressure.In addition,the health and safety of human body will be endangered.Heat acclimatization is beneficial for adapting to hot and humid environments and can improve the body's heat tolerance capability.This research was supported by the General Program of the National Natural Science Foundation of China(Grant No51378337).The experiment was conducted in this paper to study the effect of heat acclimatization on human,the time required to the heat(in days),and the relationship between thermal parameters and heat acclimatization,which is for developing a theoretical basis for heat acclimatization in a hot environment and providing information that is useful to occupational health agencies to facilitate appropriate heat acclimatization training.In this paper,a climate chamber was built to simulate a hot and humid environment.Sixteen healthy male university students were selected as the subjects asked to run at a speed of 5 km/h to simulate heavy manual labor in the chamber.The temperature and relative humidity in the standard testing mode was 36?-50%,and the temperature and relative humidity in the heat acclimatization training mode were 36?-50%,36?-70%,38?-50% and 38?-70% respectively,and the physiological parameters such as heart rate,blood pressure,respiration,skin temperature,rectal temperature,sweat production,two-point threshold,fatigue degree,thermal sensation,mood and work efficiency were measured.It could be found from the data in the experiment that,the effects of heat acclimatization are significant on cardiovascular system,respiratory system,energy metabolism rate,temperature regulation system,body fatigue and work efficiency.Heat acclimatization training could reduce the effects of thermal parameters and work intensity on heat stress responses and improve biological adaptations.The time required to acclimate to the heat(in days)was determined based on the standard of thermal adaptation improvement.A Cox regression method was adopted to rank the effects of several variables on heat acclimatization to determine the relationship between thermal parameters and heat acclimatization.Both the temperature and the relative humidity significantly affect heat acclimatization,with the effect of the former being more significant.Finally,the development of heat acclimatization was quantified to analyze the forming mechanism of heat acclimatization.