Implications of indoor air temperature variation on the health and performance of Brazilian students

Abstract

The aim of the present study was to evaluate the relationship between cognitive performance, health and environmental comfort as a function of indoor air temperature (Ta) variation. A total of 360 undergraduate students were subjected to the variation of the Ta at 20, 24 and 30 °C; their thermal responses were evaluated over three consecutive days. Performance variables measured in the study were cognitive performance, blood pressure, heart rate (HR) and comfort. The environmental variables measured were Ta, globe temperature (Tg), illumination, noise, airflow velocity and air quality. The variation in HR was influenced by the variables, relative air humidity and mean radiant temperature (Trm) during the three days of observation, where HR was higher than 100 bpm when Tg was greater than Ta. Trm increased proportionally to the increase in Tg, thus characterising heat exchange by radiation. The number of correct answers and test response time were also positively influenced by Trm when Ta was 20 °C. Teaching environments (TEs) with increased heat load due to the individual body heat of students, increased outdoor Ta and urban morphology associated with the building of the TEs result in increasing in Trm due to the Tg being higher than the air temperature, with possible impacts on health and performance variables.