In the desert, there are two main sources of water: groundwater and water retained by plants. The quickest and surest way to get water is to cut off the top portion of a cactus and squeeze the juice out. Place some pulp in your mouth and drain the pulp of all liquid and discard the pulp. If no cacti are near, find a low area of land. Dig deeply until water begins to seep in, and drink.
The hot desert sun can be unforgiving. It can blister your skin and cause you to sweat every last drop of water out of your body. However, shaded areas have the potential of being as much as 20 degrees F cooler than direct sunlight. Building a sun-blocking shelter will aid in keeping you hydrated and prevent serious sunburns. To build a shelter in the desert, locate a large piece of sun-blocking cloth. Use rocks to anchor each side of the cloth, leaving a gap for you. If lost in a sandy desert, seek out a low area and dig a trench to rest under the surface of the sand. The area below the surface is much cooler than on the surface.
When lost in the desert, your best chance at survival will likely come from signaling for help. There are several viable signaling methods available in the desert: fire, smoke, messages and noise. To start a fire, you will need to first collect a large arsenal of items to keep the fire going: tinder, kindle and wood or brush. Create three fires in a row or triangle as a distress signal. Start the fires using matches or glass to amplify the sun's heat. For smoke signals, place something damp on the fire, or light a car tire on fire to get attention. To create a message, lay out extra clothing or materials to spell out your message. For an audio cue, carry a whistle. When you hear people nearing, blow it loudly. You can also use mirrors to angle sunlight up toward planes to get their attention.
The old saying, "Desperate times call for desperate measures," most certainly applies to desert survival. When it comes down to it, everything is food. Insects are high in protein and can be found anywhere on the planet. Search under rocks or dig for this meal. Reptiles are also a good option because they, too, are high in protein. Additionally, reptiles are fairly easy to catch. If possible cook all reptiles before eating. Mammals are also a great food source. However, most desert mammals come out only at night, making them hard to catch.