| With the frequent occurrence of high temperature events around the world,the high temperature environment greatly threatens the physical and mental health and safety of the human.For some elderly people who look forward to staying indoors,their physical health is more susceptible to the adverse effects of indoor high temperature.Therefore,research on the physiological stress and thermal comfort of the elderly in the indoor high temperature environment;Analyze the impact of environmental parameters and physiological parameters on the thermal comfort of the elderly;Determine the neutral value and acceptable range of the environmental parameters of thermal comfort for the elderly and the neutral value of the average skin temperature;And establish a comprehensive environmental index based on the subjective and objective parameters of the elderly to evaluate the comfort of the indoor environment.It can provide theoretical basis and basic data for studying the indoor comfort of the elderly in high temperature environment,and also provide an accurate and scientific evaluation method for evaluating the comfort state of the elderly in high temperature environment.In this paper,on-site measurement is used to study the physiological stress and thermal comfort of the elderly.20 elderly people are selected as subjects,and the indoor environmental parameters and the subjects’ physiological parameter data are collected as well as the subjective parameter questionnaire survey.First,based on experimental data,logistic regression and ROC(Receiver Operating Characteristic)curve analysis methods are used to analyze the subjective and objective parameters of the elderly.The results show: the subjective parameters and diastolic blood pressure of the elderly are jointly affected by dry bulb temperature and relative humidity.The mean skin temperature and forehead temperature are affected by the combined effects of dry bulb temperature,relative humidity and wind speed.The eardrum temperature is affected by the dry bulb temperature,black bulb temperature,relative humidity and wind speed.The heart rate is affected by both the dry bulb temperature and the black bulb temperature;All subjective parameter models are statistically significant(P<0.05),and the average skin temperature is more significantly affected by environmental parameters than other physiological parameters.The evaluation of the influence of dry bulb temperature on the eardrum temperature,thermal comfort,thermal sensation,thermal acceptance and wet sensation of the elderly has high accuracy,and its AUC(Area Under the Curve)is 0.720,0.639,0.760,0.814,respectively,0.685.Relative humidity has a high accuracy in evaluating the impact of thermal expectations,and its AUC is 0.872.The evaluation of the impact of environmental parameter models on forehead temperature is almost meaningless.Secondly,the difference between the sensitivity of the elderly and the young to environmental parameters were studied.By using linear fitting to determine the relationship between human body heat/humidity sensation and subjective and objective parameters in high temperature weather,the acceptability of environmental parameters for the elderly and young people were studied.The results show: the heat sensitivity of the elderly is lower than that of the young;The moisture sensitivity of the elderly is higher than that of the young.The sensation of heat and wet of the elderly is slower to respond to changes in their skin temperature than that of the young.The neutral temperature of the elderly and the young are 29.5℃ and 27℃ respectively,and the acceptable temperature ranges are 28.5～30.4℃ and 26.3～27.9℃ respectively.The neutral relative humidity of the elderly and the young are 62% and 57% respectively,and the acceptable relative humidity ranges are 55～69% and 48～66% respectively.The thermoneutral skin temperature of the elderly and the young are 35.9℃ and 35.7℃,respectively,and the wet neutral skin temperature are 35.6℃ and 36℃,respectively.Finally,the optimal group of indoor environmental parameters for the elderly was studied and the Comprehensive Environmental Index(CEI)was established.First,by using orthogonal analysis and matrix analysis to calculate the weights of environmental indicators,the optimal group of indoor environmental parameters is obtained,and the environmental parameter weights are compared.Finally,CEI is established,verified,and classified.The results show: the optimal group of indoor environmental parameters for the elderly is: 28°C(temperature),60%(relative humidity),and 0.05 m/s(wind speed).The weights of environmental parameters are: 0.45(temperature),0.32(relative humidity),0.23(wind speed),that is,the degree of impact on environmental comfort is temperature>relative humidity>wind speed.Based on the physical stress index PSI(Physiological Strain Index)classification,the CEI is divided into comfortable [0,0.2),a little uncomfortable [0.2,0.4),moderately uncomfortable [0.4,0.6),very uncomfortable[0.6,0.8)and unbearable [0.8,1] five thermal comfort levels.The CEI is simple and easy to measure,providing convenience for monitoring the comfort of the elderly.This paper studies the physiological stress and thermal comfort of the elderly in high temperature weather,analyzes the internal relationship between the thermal sensation and physiological stress of the elderly in the high temperature environment and the indoor environment,and scientifically reveals the impact of high temperature weather on the special group of elderly people.It can provide a theoretical basis for the health protection of vulnerable populations in hot weather,and can also provide a scientific basis for the health protection of the elderly in indoor environments in hot weather. |
