You're right to be cautious. A trip to the Mojave, or any desert, is not to be taken lightly. From Las Vegas, even short hikes and day trips can, unless proper precautions are taken, turn into life-threatening situations.
If you're just stopping along paved roads and getting out of the car briefly to shoot Joshua trees or other desert scenery or wildlife, the chances of getting into a jam are slim. Also, to capture the glorious low desert light, it's best to be on the spot at sunrise when it's coolest or at sunset when the heat of the day is dissipating. Most other times, especially in the summer, the light is flat and the glare is ferocious. If you can be out only then, a polarizing lens is a must.
If you're wandering off the beaten path, however, especially onto dirt roads, you should take a few simple steps to ensure your safety.
First, before you head out, it's a good idea to inform someone -- a friend, relative, concierge -- where you're going and when you'll be back. (And don't forget to check in when you return.) If you don't show up when you're supposed to, that person can alert the authorities.
Check your vehicle. Fuel and fluids should be full. Carry at least a gallon of water for the car (some antifreeze is also good to have) and a usable spare tire and jack. If possible, have a flashlight, flares or a signal mirror, a shovel, and a first-aid kit. Don't forget a rag or two.
For yourselves, carry a gallon of water apiece. Sunglasses, a sun hat, a loose-fitting long-sleeved white shirt, light pants, socks and boots are good insurance.
If the car starts to get hot or actually overheats, stop until it cools off. Never pour water into a hot radiator. If you smell rubber, your tires are overheating, which makes them highly susceptible to blowouts. Stop, in the shade if possible, to let them cool.
If your vehicle gets stuck in the sand, don't panic. Panic's a killer. Take it easy. Accept the situation. Don't blame yourself or anyone else. These things happen. Put the hood up on your car and tie a rag to the antennae. Decide on a further plan that maximizes your chances for health and safety. Stick with your plan unless conditions warrant a new one.
Try letting some air out of the tires for traction. If you can't get moving again, stay with the vehicle until after the sun has gone down, then try to dig it out.
Meanwhile, find shade and get out of the sun. Place something between you and the hot ground. Limit movement. Conserve sweat. Cover your head. Protect your neck with your collar or a rag. Sweat-absorbing clothes will keep you cool. By staying in the shade, not moving, not talking, and breathing through your nose, your water requirement for survival is dramatically reduced.
But drink plenty of water, a quart every hour if you can. Tiny sips of water don't get it to your brain and vital organs. Take a good drink when you need it. People have been found dead from dehydration with water in their canteens. (You can check the color of your urine: If it's dark, drink more; if it's light, you're drinking enough.)
Recognize the signs of heat trauma. Heat cramps start as muscular discomfort, then escalate into cramping of the arms, legs, and abdomen. Heat exhaustion shows up in headaches, confusion, irritability, dizziness, and cold clammy skin. Get the victim into shade immediately, making him drink water every two or three minutes. Sprinkle some on his skin and fan him. Heat stroke will kill a victim if he's not cooled immediately.
Use your signal mirror during the day; it can be seen for miles. Use your flares at night. As a last resort, send the strongest member of the party to the main road, but only after the sun is down. Most desert deaths occur from dehydration provoked by walking too long in the sun.
Your life expectancy -- in extreme heat, resting, in the shade, with no water -- is three days. Try not to verify that.
