Cumru Twp, PA - April 14: Sabrina Werley works with 4th grade student Isaiah Bungie during a math support class. (Photo by Ben Hasty/MediaNews Group/Reading Eagle via Getty Images) PHILADELPHIA - Students and staff at schools in Philadelphia will once again be required to wear masks. RELATED: Most of Delaware Valley in CDC's high COVID transmission categoryAccording to a letter posted on the Philadelphia School District's website, the district says it is following the health department's recommendation. "To help protect everyone's health and well-being as COVID-19 case counts continue to rise in the Philadelphia area, the Philadelphia Department of Public Heath (PDPH) has recommended that we resume universal mask-wearing.