AUSTIN. The city's heat-adaptation office is small, but its mandate is not: make Austin livable for the summers that are already here.

Its plan, shaded transit stops, cooling corridors through low-income neighborhoods, and a tree fund that grows with every development permit, is getting national attention from cities that skipped the first draft.

Heat is the quietest disaster. It doesn't flood a street or knock out a grid; it just taxes the people with the least shade, year after year.