2018 Yes https://pubmed.ncbi.nlm.nih.gov/29473137/ Palumbo, Jillian Europe Exposure Study Teachers Students Elementary (K-5) Temperature Humidity Noise Respiratory symptoms Vision School environment Respiratory health Children's health Romania We found increased risks for allergy and flu-like symptoms associated with hot classrooms in the heating season, increased risks for asthma-like symptoms associated with noisy classrooms, and a protective effect for allergy associated with good outdoor air quality. Romanian classrooms rely on natural ventilation, which may contribute to increased temperature and humidity in the heating season.