To all of these sage comments I'd add a few:

Water in a hydration bag with the tube covered in a light colored neoprene sleeve to keep the water in the drink tube below "boiling" temp.

Stay away feom cholla cacti !! FAR away - and never camp anywhere near them Their spines are maddeningly painful. Don't ask me how I know.

Protect your skin. Rely more on specific UV barrier clothing than sunscreen. Do like the cowboys downhere do, wear a long sleeved shirt and a wide brimmed hat and TOUGH pants like denim or, my fav, "5.11" brand nylon canvas tactical pants.They turn sharp growth...and every plant in the desert is some kind of sharp or nasty.Check out the 5.11 website.

Eric