Sara Mosle explains why air-conditioning matters.

When elected officials hear complaints about sweltering classrooms, they sometimes reply that back in the day, there was no air-conditioning.

Mosle points out that when the end of year tests are given, children in affluent districts with air-conditioned classrooms have an advantage.

When the Chicago Teachers Union complained about the lack of air-conditioning, many thought this a ridiculous demand.

Karen Lewis proposed that the administrators at central headquarters work without air-conditioning. That, of course, was unthinkable.