How well will a MacBook Air work in a hot dusty environment
I do not know about the dust (as a comment asked, it really depends on the amount and type of dust), but I would definitely not recommend using your MacBook Air as if it were heat resistant. Specific computers are assembled for warm (and damp) climates: if your MacBook Air, as I suppose, is not one of them, I would recommend that you do not take that risk unnecessarily, hoping for the best. Laptops can get damaged by lesser threats than prolonged exposure to heat, which is a serious one.