I've been out in the desert when the temperature was 115+. You feel weak and sick to your stomach. The most important thing is to get out of the sun and drink water. Water alone will not save you. You need something like Gatorade to feel OK. Whatever you do don't get out in the sun and work. The coyotes will eat your dead carcass (no joke!).
_________________________
Thermo-regulate, hydrate and communicate.