You have in there... what? Three days worth of food and water? Maybe less if you're a big eater. And the human body can survive in the desert without water for a day, maybe two if you're sturdy.

So that gives you four to five days to find civilization or water. Assuming you don't run into any predators at night, and nobody steals what you already have from you. That's a pretty big gamble, considering you know nothing about this place. Do you really want to risk it?