I've lived in AZ, only it's Tucson, not the Mesa area for almost 40 years. I don't remember our cold water being hot except outside when I turn on the hose, that's hot hot water for a minute or 3. I do tone down the hot water for my shower but we always have cold. Now Florida...ha that's another story. j/k Daily showerer op only.
Dr. Know I was kind of being a wiseazz, but I live in a cookie-cutter type neighborhood where they put the plumbing pipes just under the surface, they don't bury them deep at all. In the summer, our water is never cold and barely gets to tepid. Maybe more so in the early morning, but we get nightime temps of over 100 degrees.