Hot hot hot
I lived in Oman from 1996 to 2001 and in July and August it goes without saying that it is hot - regularly low 40s and occasionally high 40s. Obviously nearer the coast is a little cooler.
In our company, there was an edict that manual labour could be stopped on days when it used to go above 45C
Of course people live there, so moving around at that time isn't impossible. All the Expat families shoot off out of the country but I stayed through one or 2 summers and survived, although I guess I was acclimatised.
Only 2 things to consider really - your vehicle has to be in A1 tip top, 100% perfect condition before you set off - anything less is plain daft. I am all for daft, reckless arsing about (usually) but not in the midst of an Arabian Summer.
And water. Literally you will need to carry around 50 litres per person on the vehicle in many different containers - some will spill, split, get left on a rock after a stop, will be drunk and some has to stay in reserve.
But it is not an impossible task
Oh, I forgot one thing I learned - conservation of energy. Only daft Europeans race around. It took me a year or two of living in Oman to realise that one had to move like the locals. Walk slowly, one step at a time, move objects in small lightweight numbers and so on. Do everything gently and slowly and conserve your natural energies