I found one of my white bantam cochin hens (best of breed in her last show!) in my trio dead yesterday. Don't know what to do for them except keep them shaded and hydrated.
Several young ones that I had moved outside are free ranging at a younger age than I would normally allow, but they turn over their water in their pen or pile up on each other, so I'd rather have them with access to the community waterers and more shady spots. My collie Simon keeps a good eye on them and doesn't allow varmints, although he wouldn't be much good if a hawk decided to check out the yard.
Still some in the basement that are old enough to be moved outside, but it's cooler in.