I have had tire failures driving on very hot days on rough highways. If your tires are of correct type, new, and inflated properly for your rig, there is less chance of tire trouble in beastly hot weather. Take frequent breaks at rest stops to relax from the pounding and stress of hot weather driving. Drink plenty of water. Use your brakes and transmission properly on grades to avoid brake fade. Avoid driving at peak temperature times. We don't RV in 90+ weather, prefer to stay home with good central air conditioning.