For young students with August return dates, school has already started — and for many of them virtually. However, millions of students' and teachers' school plans hang in the balance, as aging school HVAC systems confront the novel coronavirus.

Nowhere is this more evident than for the students of Dennis-Yarmount Regional School District, located on Cape Cod, Massachusetts. District officials, teachers, students and parents are awaiting a report from August inspections made on the HVAC systems of the district's six schools, which will ascertain the systems' abilities to provide proper ventilation to reduce risks of coronavirus transmission among students in classrooms. Four of the district's buildings are 50 years in age or older, and two of those are set to be replaced by facilities under construction, driven in part by previous concerns over aging HVAC infrastructure.

It would be really hard for the school committee and the administration to tell the community their students and their teachers should go back to buildings that may not be safe, said Michelle Dunn, teachers union president, to the Cape Cod Times.

Students are set to return to school by September 16, which means officials will have just a few days to adapt to new plans for students, should the inspections show that the HVAC systems are insufficient. Children in grades 7 and below are planning to be in class five days a week; older students will be in class two days a week, with the other three set for remote learning.

At nearby Nauset Regional High School, a lagging HVAC system prompted administrators to move the school year completely online, at least for the first part of the school year. Massachusetts remains one of just a few U.S. states where COVID-19 cases have been relatively stable, but schools have placed high priority on student and staff safety.