Stephanie, it sounds like you're doing lots of things help them out, which is great. Providing shade and fresh water are the two most critical things you can do. There are lots of others though and you can read about many of them in this link: http://www.the-chicken-chick.com/2012/04/beat-heat-how-to-help-chickens-survive.htmlWe have had 100+ days for over a week, very hot. Feels like I am being cooked when I go outside, so of course I worry about my chickies.
I positioned my brooder in front of an open door to a furnace room which receives some of the AC from the window unit on the living side of the furnace room, so the babies are staying cool while in the brooder. When I put them in an enclosure inside the run for a little while today, I poured water all over the ground and added some extra branches with many leaves for added shade. I also add ice to their water bowls.
The big birds seem to be doing okay, though panting quite a lot. An area of their run, about 8x4, never seems to get any sun because of the trees and the position of the shed (coop) The large birds stay there all the time, but each time I check on them, the temp seems at least 15 degrees lower than everywhere else. I do have a kiddie pool in my run. It is essential to change the water everyday by early afternoon because it heats up very quickly. Some of the birds will stand in the cool water on occasion, not too much. My opington roo dunks his entire head in to drink and seems to really love the water running down his face and neck.