during my summers in arid-zona. i installed an aux fan on the outside/back of the refrigerator, by circulating more air through the heat exchanger.. it was able to deal with the hot desert air.
also i found a small window a/c to help cool the r.v. as the factory unit couldn't keep the r.v. cool.. i bought the r.v. with the largest btu unit available...
if you get into a dust storm, turn off the a/c. as some dust storms are combined with a thunderstorm. the moisture will turn the dust to mud, that hardens like brick. which is a challenge to clean from the a/c condensing coils...