Outdoor Thermal Comfort and Cognitive Performance of Older Adults in Singapore: A field quasi-experiment

Abstract

This field quasi-experiment with 109 older adults examined their cognitive performance in outdoor naturalistic environments and how it is potentially influenced by the Physiological Equivalent Temperature (PET) index (proxy for outdoor thermal comfort (OTC)) and individual climatic conditions (i.e. air temperature, relative humidity, mean radiant temperature and wind speed). Cognitive performance was evaluated when older adults performed physical and sedentary outdoor activities in residential and commercial areas at different times of the day (i.e. morning, afternoon and evening) using a Stroop game. Besides, we collected socio-economic and demographic characteristics and lifestyle data of the participants. Overall, our results show that a higher PET (could also be interpreted as a lower OTC) was negatively related to older adults’ cognitive performance. Wind speed improved cognitive performance while air temperature, relative humidity and mean radiant temperature have detrimental effects on their cognitive outcomes, however in dissimilar magnitude. Social isolation, the use of air-conditioning at home, low levels of educational attainment, poor self-rated health and the engagement in sedentary activities were also related to poorer cognitive performance. These findings suggest that older adults’ cognitive performance was poorer when OTC was lower and this effect might be exacerbated by lifestyle and demographic characteristics. Further investigation into the effects of the lower OTC on older adults’ cognitive performance in different areas of Singapore will be useful for the identification of potential mitigation and adaptation actions.