Indoor environmental quality (IEQ) in school buildings is crucial for the health and well-being of students, educators, and staff. Poor air quality and inadequate thermal conditions compromise students’ comfort and can lead to potential long-term health issues. Since children’s comfort differs from adults’, it is important to consider surveys on IEQ in school buildings. For this reason, this paper focuses on air quality and thermal comfort in kindergartens in Italy. An IEQ monitoring campaign was conducted within a kindergarten, with data used for thermal comfort and IAQ analyses, including CO2 levels generated by occupants and thermal discomforting hours. The simulations of carbon dioxide levels showed that the amount of CO2 accumulated in the classrooms exceeds the threshold recommended by ASHRAE guidelines. During the winter seasons, CO2 levels are significantly higher than those accumulated in summer due to the limited ventilation practiced during the colder months. Moreover, thermal comfort analyses indicate that the summer season can be problematic due to overheating: 42% of the occupied hours during the monitoring period exceeded the temperature threshold, causing thermal discomfort for the occupants. The winter thermal comfort analyses demonstrated that heating systems are essential to maintain temperatures within comfort thresholds.
