If you want to minimize the effect of high temperature conditions, then you might want to keep in mind these considerations.
First of all, consider purchasing a high quality module with a low temperature coefficient. HIT modules from Panasonic have the lowest temperature coefficient at -0.258 % / °C, that can be a good starting or reference point.
Second, consider installing a ground mount instead of a roof mount to maximize air cooling. Finally, for desert areas, a water cooling system may be a useful addition to the PV system to bring temperatures of the module down and make it operate more efficiently.