Errr, nights in the desert are usually freezing cold, not extremely hot.

As far as the temperatures are concerned, they look like nothing to worry about to me. Though you may want to upgrade your cpu cooler. As far as applying new pasted to the gpu core it may void your warrany, but doesn't have to, depending on the manufacturer, XFX is modder friendly in that regard.

It's cold in the desert at night, actually (I live in one).