Bubbler setup too hot

[evaunitone]

I have a bubbler setup running in a large tupperware container with tomatoes and some green beans. The green beans seem ok, but the tomatoes have started wilting today in the heat. It's very hot here (Denver) today and I'm not sure what to do about it. The plants have been growing amazingly over the last few weeks but since I drained the bubbler and replaced it with pure water (no nutrients) to flush out the salts in the plants temporarily, the roots have become slightly brownish and the tomatoes are wilting. Is it because of the heat? If so what can I do? If not the heat then what? Please help. I LOVE my tomatoes