Snakes do not like the direct heat of the sun, so in the daytime they are usually in holes, under logs, or in rock piles. The best advice, then, is not to put your hands or feet where you cannot see them. Scorpions can be nasty little critters, too. They also are nocturnal, so use the same precautions as with snakes. If you camp out, be sure to check your boots in the morning before putting them on.
Scorpions are notorious for hiding in boots.
This advice, if followed, will make it possible to have a very safe desert trip. In fact, you may go for years and seldom, if ever, encounter a snake or scorpion. There are some manmade hazards on the desert, too. Old mines are always dangerous, but the desert mines are especially so. Unlike the hardrock mines in the mountains, desert mines are often dug in sand and shored up with timbers.