Kind of strange question, lol

[kenyonchris]

Ugh. Try here in Texas in August for the Hotter n' Hell...we have humidity too, so sweat doesn't evaporate. It just sits there in a hot puddle.
I was using water in one bottle, gatorade light or diluted gatorade in another. My semi-pro BF is sponsored by Hammer Nutrition, so I started using the Heed in both water bottles. I felt SO much better that now I carry powdered Heed with me and when I refill I remix the Heed. Hammer suggests Perpetum for long rides, but I just don't like the taste.
And once it starts getting hot, I stay out of the gym. It is too cold in there, and it makes doing anything outside just seem hotter (sort of an unscientific lobster theory....it hurts less if the water heats up with them in it, rather than plunging them headlong into the boil). I find that because I am outside all the time, I can tolerate it better than someone who moves from in to out more often. There may be NO validity to the theory, but it works for me!

[tctrek]

My bike computer registered 100 degrees on todays ride. We drank 2 large bottles with electrolytes and carbs + one bottle of just water in 3 hours. I also like the new Marguerita Shot Blocks - they actually have salt!! When I got home, I was amazed at how much dried salt was on me -- sufficient amount that my arms were white with it.

We didn't get started until about 11 am, which was wrong. Time to start getting out there much earlier.

[OakLeaf]

This site has a wide selection of evaporative and solid-liquid phase change cooling apparel. I don't have any experience with this site - the place where I bought mine is apparently out of business - I just put the link up because they had so many different choices you could see.

It occurred to me that in the desert, an evaporative vest would probably work just fine at bicycling speed. In the humid east, more air flow is needed.

I haven't had good luck with the bandana things, but I know some people really like them. To me, they just insulate my neck, and the coolness from the evaporation on the outside layers never reaches the inner surface. Maybe, again, ambient humidity and reduced air flow from my short neck are the reason for that.

[Crankin]

You have a lot of good suggestions.
I just want to add that I lived in Tempe for 16 years and I can't imagine doing the kind of riding I do now, in that climate. I used to get up and walk at 5 AM and that was 25 years ago; I spent most of my time at the gym.
Now, riding October through March will be great, but I would be very careful. Heat exhaustion is nothing to fool around with.