Summertime Thermal Comfort And Physiological Responses Among Activity Levels In Campus Outdoor Spaces

Campus outdoor open space,as an important place for outdoor activities and communication between teachers and students,plays an important role in improving the microclimate of the campus,attracting more users,and promoting the health and well-being of teachers and students.Outdoor thermal comfort of human body is not only affected by microclimate factors,but also affected by activity intensity.However,there are few studies on the influence of different outdoor activity levels on thermal comfort.Therefore,in order to explore the physiological and thermal responses of human with different activity intensity in campus open space,physiological responses and thermal comfort of 54 healthy college students while undertaking different physical activities(light,moderate and vigorous intensities)in six campus open spaces(playground=PL,waterfront square=WS,square=SQ,atrium=AT,tree-shaded area=TS,pavilion=PA)were investigated using meteorological measures,longitudinal questionnaire surveys and physiological parameters.Physiological Equivalent Temperature(PET)and Universal Thermal Climate Index(UTCI)were chosen as the thermal indices,while blood pressure(BP),heart rate(HR)and skin temperature(ST)were selected as physiological evaluation measures.Results demonstrated that: 1)As activity intensity varied from light to vigorous,the preference votes for lower air temperature and higher wind speed increased,and the preference for relative humidity and solar radiation did not change significantly.2)As activity intensity ranged from light through moderate to vigorous,neutral UTCI declined by 27.6℃,25.6℃,22.0℃,and neutral PET declined by 26.1℃,22.1℃,11.9℃.3)There was no significant difference in human thermal sensation in high sky view factor(SVF)spaces.Outdoor spaces shaded by trees or pavilions were more comfortable for outdoor activities than these with low or middle SVF during summer.Considering all activity levels,spaces ranked by mean thermal sensation vote(MTSV)were: WS>PL>AT>SQ>TS=PA.4)Thermal symptoms were positively related to activity intensity and SVF of spaces.The proportion of volunteers developing thermal symptoms under light,moderate and vigorous intensity PAs in stage 2were 33%,50% and 83%,respectively.5)BP and HR reflected human activity levels.HR clearly represented metabolic trends.6)ST accurately represented physiological responses among spaces across activity levels,and its change was closely related to SVF.At moderate and vigorous intensity PAs,MST was 0.25-0.5℃ lower than that at light intensity PAs,MST in semi-shaded and shaded spaces was about 0.8 ℃ and 1.3 ℃ lower than that in un-shaded spaces.7)Mean skin temperature(MST)was poorly related to thermal sensation vote(TSV).8)The design of campus outdoor activity space should be based on the thermal comfort standard and microclimate conditions,through plant shading,plant layout,landscape facilities,spray,to create appropriate outdoor activity space,on the basis of considering terrain,plant landscape,security.This makes the outdoor activity space more attractive and provides the basic guarantee for the promotion of national fitness.