Effect of a cool classroom microclimate on symbolic indexes of cardiac autonomic control and cognitive performances in undergraduate students

Working and learning capability were found to be impaired in a setting of uncomfortable indoor microclimate conditions such as warm temperature and/or poor air quality [1], [2]. In a previous study [3] we observed that an increase in classroom temperature of about 2°C from a “neutral” temperature set point (22.4 ± 0.1 °C) during a lecture, induced students' subjective thermal discomfort and a shift of the cardiac autonomic control towards a sympathetic predominance. In addition, during the warmer condition the student's cognitive performance was significantly impaired [3]. Other authors reported a progressive increase of cognitive achievement for every 1°C of temperature decrease [4] within the classroom temperature range of 20–25 °C, suggesting an inverted U-shape relationship between ambient temperature and cognitive performance peaking at 21.6°C [5]. Little is known about the effect of a cool classroom microclimate on cardiac autonomic control and cognitive performance of students attending a 2-hour long lecture.