We spend a lot of time camping in the south west in the Desert camping in the RV such as Moab and Zion. The heat getting to 115 is often considered cool out there at times.
In regards to the TT we finding cooling it early and maintain a constant temp is easier than bring it down from very high temps to 72. When the inside reaches say 90 because of the heat trying to lower it quickly can be hard to do. So maintain a 85 during the day is easy.
Use awning to cool the trailer while you there. What the winds to come up out in the desert.
If you have selection of shade pick the west shade to help in late afternoon heat.
While doing outside activity, drink water, water, water and then more water. For thoose not use to the desert heat can get serious effects of the dry heat very quickly.
Enjoy this golden gem of the desert.