How can we prepare for hotter summers?

I know we're still dealing with snow and ice but last summer was brutal and I'm already dreading it. My AC was running nonstop and barely keeping up. What can we actually do to make the heat waves more bearable? More trees in neighborhoods that need them? Opening up more cooling centers? Better access to beaches and public pools? Those L platforms were easily 110 degrees last August and I can't do that again. What are some realistic solutions that would actually help?