New Delhi, Nov. 5 -- Delhi-NCR's winter has arrived. Air quality is deteriorating, and the Graded Response Action Plan (GRAP) has already started shaping daily life. Residents will now welcome an occasional improvement from "severe" to "very poor" as progress. Amid the restrictions, one demand is likely to grow louder: move schools into hybrid mode. In practice, some schools may default to online classes.

Parents anxious about their children's lungs have legitimate concerns. But parental anxiety cannot substitute for evidence in public policy. Whether classrooms should close during severe pollution must be decided before the next emergency, guided by proportionality, equity and measurable benefits. Online instruction may preserve contact...