Study shows why opening windows in class will not stop COVID-19

Open windows in a classroom may give a false, or incomplete, impression of good ventilation. Cold surfaces, such as windows, can pose an additional risk in enclosed spaces. The key to reducing transmission is to limit horizontal airflow at the breathing level. To reduce SARS-CoV-2 exposure indoors, it is crucial to space seating according to guidelines, wear masks, and keep windows open.