Oogie Boogie was here.
Do you have a map? Which direction would be closest to the next town? If you were not to far from help then leave your vehicle at dusk, and walk at night when the heat isn't as severe. Walking in the heat of the day is a fool's errand. If help is to far away staying put and building shelter would be the best option. You are adequately supplied, and your friends should start looking for you, or at least alert authorities that you are missing.
Patrick, what would YOU have done had you been unable to restart your vehicle??