Larry, that's right, that was the thread I was referring to.
Having gardened in a number of different climates I just want to add that humidity is a factor too in high heat, and not just for human comfort or lack of it. Plants (unless they are maximally xeric types) growing in heat under low humidity conditions are still going to need more water and attention than plants growing in the same temperatures in high humidity. 99 degrees in central Washington is different than 99 degrees in Florida (for instance) because that dry air sucks the moisture from everything it touches.
