2019 Yes https://pmc.ncbi.nlm.nih.gov/articles/PMC6518471/ Temte, J. L. North America Observational Epidemiology Study Modeling Students Other Elementary (K-5) Middle/Jr High (6-8) High School (9-12) Temperature Humidity Respiratory symptoms Influenza Respiratory infections Transmission Time series analysis of ARI diagnoses from Wisconsin clinics showed increased risk when schools were in session; findings inform public health outbreak interventions.