Thermal sensation and indices in the urban outdoor hot Mediterranean environment of Cyprus

Several thermal indices have been proposed for quantification of various aspects of the thermal environment. Their applicability however is a methodological conundrum. The aim of the present study (part of the Biometeorological Aspect of Thermal environment and Health (BeAT Heat) project) was to assess the outdoor thermal environment using data on thermal sensation. In particular, the study tried to identify the thermal index that best simulates thermal sensation in the temperate and dry Mediterranean climate of Cyprus. Field surveys were conducted in summer 2019 in public urban spaces of five districts in Cyprus. These surveys involved monitoring of micrometeorological conditions and conducting questionnaire-based interviews with pedestrians in order to collect data on actual thermal sensation (ATS), demographics, and physiological and psychological variables. The study participants, using a predefined thermal sensation scale, reported their ATS. Variations of thermal sensation across the participants were studied in relation to the outdoor thermal environment and to physiological factors. ATS was compared with simulated thermal sensation (STS) produced by operationally used thermal indices under matching weather conditions, i.e., Heat Index, Humidex, and Wet-Bulb Globe Temperature. Physiologically Equivalent Temperature was additionally considered. All indices showed low predictability of ATS. The thermal index that performed best to the temperate and dry Mediterranean climate of Cyprus was the Heat Index using an assessment scale modified for the Mediterranean climate.