text:  but says it falls short. It's an option, not a mandate, he says, and residents must ask for the help. They might not get the notice in the first place that this is a thing, and the residents might not apply in time when the heat strikes. People in public housing are disproportionately vulnerable to heat illness, but even some who have AC units may not use them in order to save money. Jennifer Ludden, NPR News, Washington.