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Coaches, athletes, and spectators must wear face coverings if they cannot maintain sustained physical distance from persons outside of their household. This includes while actively engaged in workouts, competition, and on the sidelines, in the dugout, etc. If sustained six-foot distancing can be maintained, face coverings may be removed when outdoors. 
Using football as an example, wearing a mask in addition to a mouth guard and a helmet would likely create a medical issue for the athlete whether the athlete is a professional or youth player even if a previous medical issue was not present. For example, the CDC says that "wearing a mask with these types of protective equipment is not safe if it makes it hard to breathe." There are other sports where there are similar concerns that a mask would create a medical issue where one would otherwise not exist in an athlete. 
Our Board understands that some parents may wish for their child to wear a mask at all times despite CDC guidelines. Our Board is following the PIAA recommendations and parents assume responsibility for their child’s health if they choose to enforce mask wearing during play.  Coaches will not be responsible for that child keeping their mask on.  The Board asks that parents and other spectators observe the 6' social distancing from other families on the sidelines out of respect for the safety of themselves and others.