| In the current period of rapid industrial development in China,there are more and more high-temperature industries,and the high-temperature environments are more and more common.The frequent occurrence of thermal injury events poses a serious threat to the health and life of employees.Many scholars have done a lot of work in this field,but there is still a lack of systematic research on the effect mechanism of environmental factors,and no convincing consistent conclusions have been obtained.In addition,there are many defects in the evaluation of human thermal state under high temperature environment and the existing evaluation indexes of human physiological state;Moreover,the research on human thermal safety classification and detailed man-agement in high temperature environment also has great limitations,and the relevant standards in this field can not be better applied to actual production.Based on the above problems,this study focused on the effects of high tempera-ture environments on human body,and carried out a large number of real human ex-periments in the environmental chamber to study the effects of different environmental factors(air temperature,relative humidity,wind speed and radiation intensity)on hu-man heat strain.The number of subjects was 290.Physical labor was simulated by subjects moving on a treadmill;During the experiment,the body parameters and labor efficiency of the subjects were measured in real time,and a large number of experi-mental data were obtained.Through data analysis,it was found that during physical labor in high temperature environments,various environmental factors have significant effects on human physi-ological strain and labor efficiency(p<0.05),but different physiological parameters have different effects.Moreover,thermal sensation and subjective fatigue scores were also affected by different environmental factors.Based on the experimental results,the influence weights of environmental factors and labor hours on physiological parameters were studied by using the methods of statistics and machine learning.The results obtained by the two methods were highly consistent.The results showed that the influence weights of different factors on the main physiological parameters of human body were different,and the sensitive factors were sorted.According to the experimental results,from the three dimensions of oral temper-ature,heart rate and skin temperature,a comprehensive evaluation index PSI_R in high temperature environment was established to quantitatively describe the human physi-ological heat strain.Through comparative analysis,it was found that PSI_R index was more sensitive to environmental changes and more suitable for complex high temper-ature environments;According to its relationship with labor efficiency,the body fa-tigue can be divided into four states.Combined with PSI_R index and main physiological parameters,through cluster analysis and discriminant analysis,the heat safety level and risk assessment in high-temperature working environments were carried out.The heat safety in high tempera-ture working population wad divided into four levels and five levels,respectively.This classification method overcomed the subjectivity and limitation of only classifying the environment in the previous standards,put forward the basis and reference for the clas-sification management of high temperature heat exposure,and realized the improve-ments of the existing standards.Through comprehensive consideration,it was more discriminative to divide the heat safety level into four levels. |
