How to cope with the heat

From an experienced "no A/C" camper that spends a lot of time in hot hot Eastern Washington:

Park on gravel or grass if possible and wet down the ground under the rig- and under your lawn chairs, too, if you spend any time sitting outside. The cooling power of the evaporating (or transpiring) water is really remarkable!

1/2" Foil faced foam board. Trace it to be a snug fit to the window frame, then paint the outside white (Looks less tacky) with gloss paint. Insert into windows to boost insulation efficiency, also using thicker foam board make tight fighting reflective inserts for your roof vents as well, as these are major hot/cold leak points because of the lack of insulation.

Beyond a shady site, keeping shades closed, and running fans not much you can do.
Add a second AC before next year. We added a second after a couple camping seasons. Good thing we did as our very next trip was Palo Duro Canyon when it was 108! The second AC sure makes cooling down faster after a long hot day driving.

Keep some fans running. It's tough when it's that hot, the a/c barely keeps it comfortable.

I do carry a gel mat for each dog that helps cool them when they lay on it. YOu can also get neck kerchiefs that you soak in water and put on the dog. Keep plenty of water down for them.

Keep the curtains closed.

Park in the shade! :D