Latest Pennsylvania Department of Education guidance: https://www.education.pa.gov/Schools/safeschools/emergencyplanning/COVID-19/SchoolReopeningGuidance/ReopeningPreKto12/PublicHealthGuidance/Pages/default.aspx
Latest CDC Guidance: https://www.cdc.gov/coronavirus/2019-ncov/community/schools-childcare/prepare-safe-return.html