Summer heat in Phoenix w/Class A... need some input

yes but if you can block the sun from radiating thru the windows you'll be ok. take a ride to home depot, lowe's or even the camping world on main street in mesa and get a roll of the corrugated foil window shields. cut it to fit your windows and you'll be surprised at home much cooler your RV will be. also try to get a site that faces north, northwest or west. avoid southern exposure at all costs.