Step one comes when you order/choose the RV, avoid black like the plague, In fact all dark colors
Make sure you have awnings, epically on south and west sides,
SHADE, even if you have to provide it artifically.
Refletx (Silver stuff) on the widows, Outside is better but inside is easier and lasts longer (outside the first stiff breeze and away it blows).
And make sure you are on a full power site and run the A/C.. About all i can advise.
One thing I did that helped, or seemed to... I had a portable swamp cooler,, Now these are, well, humidifiers, (Evaporation of water sucks up a lot of heat).. this increased the humidity (Good for me, I need a bit more than Arizonia (QZ) in Jan) and also it seems it made the Roof top units work better,
However, frankly I do not suggest it, too much bulk for the benefit.
