Interferences of skin colour on pedestrians' thermal perception

Abstract This study analyses effects of skin colour on pedestrians' thermal perception in outdoor spaces. The field study was carried out in downtown Rio de Janeiro, evaluating thermal sensation and thermal preference votes of passers-by. Responses from structured questionnaires were compared to data from the outdoor comfort index UTCI (Universal Thermal Climate Index), by means of data grouping according to skin colour categories provided by the Brazilian Statistical Institute IBGE. In this case, skin colour was informed by the interviewees. The monitoring took place during late spring/summer periods between 2012 and 2015, typically from 10am until 3pm. A Davis Vantage Pro2 weather station was used while, at the same time, the researchers administered a structured questionnaire based on the ISO 10551, to which a question regarding skin colour was added. The comparison between thermal sensation and thermal preference from the point of view of skin colour demonstrated that while the group with white skin showed greater tolerance to heat, they preferred cooler conditions to help neutralise heat stress. Statistical differences were only observed in the aspect of thermal preference between the groups analysed.

摘要 本研究分析肤色对户外空间行人热感知的影响。野外研究于里约热内卢市中心开展，对路人的热感觉与热偏好投票结果进行评估。研究依据巴西统计研究所（IBGE）提供的肤色分类标准对数据进行分组，将结构化问卷的回复数据与户外舒适指数通用热气候指数（Universal Thermal Climate Index, UTCI）的监测数据进行对比，本次研究的肤色信息由受访者自主申报。监测时段为2012年至2015年的晚春与夏季时段，通常为每日上午10时至下午3时。本研究采用Davis Vantage Pro2气象站开展环境监测，同时研究人员基于ISO 10551标准实施结构化问卷调查，并额外增设了肤色相关问题。从肤色维度对比热感觉与热偏好的结果显示，白皮肤人群对高温的耐受性更强，但他们更偏好凉爽环境以缓解热应激。仅在热偏好维度上，各组别间存在统计学差异。