Study On Analysis And Forecasting Model Of Human Physiological Stress Reaction In Low Temperature Condition

The northeast and northwest regions of china are severely cold in winter which will be prone to cold waves,rain,snow and freezing.The extremely harsh low-temperature environment led to a serious threat on the physical and mental health and work safety of human body.The workers especially in mountains,plateaus,underwater,low-temperature workshops of modern factories and field rescue,need to work for a long time in severely cold environment.And cold environment exposure will bring great risks of frostbite.Thus skin temperature as an important indicator for evaluating the degree of human cold stress,plays an important role in buliding a human body cold stress prediction model for workers and accurately predicting the risk of frostbite in low-temperature environment.This article analyzed the low-temperature injuries that workers often face in low-temperature.The relevant technical standards at home and abroad were studied,and the performance of cold stress response of human on physiological parameters and subjective feelings in low-temperature was also described.The ambient climate chamber was used to simulate the low-temperature environment,and three experimental temperature gradients were set,namely-5℃,-10℃,-15℃.Considering the ambient temperature and clothing thermal insulation,basal metabolic rate,body mass index,body fat rate and other factors comprehensively,8 healthy young men were selected as the subjects.Wireless skin temperature measurement system was used to measure the skin temperature of 5typical body segments,which included chest,arm,thigh,calf and toe.The blood pressure and heart rate of the subjects was measured by the electronic sphygmomanometer every 10 minutes.The subjective thermal sensation(Thermol sensation vote,TSV)during the low-temperature experiment was obtained through a questionnaire.After returning to room temperature from the low-temperature climate chamber,the time required for each segment reaching the lowest temperature based on the skin temperature data was summarized,and used to verify the influence of different rewarming methods on each segment.Based on the above work,the skin temperature change of 5 typical body segments with time was obtained under different low-temperature and clothing thermal insulaton.Through data analysis software statistical product and service solutioons(SPSS),an optimized prediction model was established,which realize accurate prediction in a short period about the skin temperature of each segment.The rhythm of blood pressure and heart rate was obtained under the conditions of sudden drop in low-temperature and indoor rewarming.The influence of body fat rate on basal metabolic rate before and after low-temperature experiment,and on chest and thigh temperature during the low-temperature was also analyzed.The relationship between the subjective perception of human body and the skin temperature of each body segment was established,and the temperature range of different segments of the thermal neutral was determined.The physiological reaction of workers in low-temperature environment was summarized,and the safe skin temperature threshold and retention time of human body was obtained.It indicated that the average skin temperature was no less than31.5℃,and the toe temperature was no less than 15℃,which means the retention time near the critical toe temperature shouldn’t exceed 30 minutes.This study can provide data support for reducing the proportion and degree of frostbite of workers,designing thermal clothing for residents,and the development of personal protective equipment for special rescue groups in cold areas.It also offered theoretical basis for reasonable length of work time in field and scheduling strategies for workers in low-temperature.