In a site with FHU's you should be ok. Comfort level will depend on size and insulation value of your trailer. Shade is a biggie if your insulation value is just average. Those with winter/thermal packages and dual pane windows will fare better.
For every 2-3 bottles of water, drink one Gatorade. This way you get back some electrolytes you sweat out.
Snakes are generally not out in the heat of the day, they hide from the heat and hunt at night. Early mornings and late evenings you may see some.
No biggie, been in Phx for 44 years and still love it.