Every year, a group of my friends go on a week-long camping trip in a Nevada desert. Sounds silly, right? No trees, plants or animals, no running water. Not even roads--usually the nearest hospital is well over an hour away, sometimes two, and that's if you don't get lost by trying to cut across an impassable part of the desert trying to get to it. But, it's a good test to see if we can be self-sufficient for even just a week. Also, in a bug out situation, some people may just find themselves having to cross through barren desert to get to someplace safer (say from Southern California to Southeastern Oregon, Idaho or Wyoming). Our rules? Bring everything you need to survive, and plan to leave no sign of our passing.
One week might sound easy, but when you start thinking about what you actually have to face in the desert, you realize that's not as easy as it sounds. With no life for miles around, it forces us to literally bring everything we need to survive. Every bit of water, food, medicine, first aid, and clothing that we might need. When you take into consideration the time of year, that adds up quickly with even just five people. We try to do this some time in August, when daytime temperatures often get over a hundred, and in years past it has even gotten to 120. Contrast that with the nighttime temperatures that can be into the low 40s, and you have a tremendous temperature spread to prepare for.
For dealing with the high temperatures, we plan on very lightweight, loose clothing. Light colors are best. I tried wearing a dark blue sarong last year and it ended up dying my skin blue because of how much dye is needed to maintain dark colors. My friend who wore the orange sarong was much better off. And for those of you who don't know what a sarong is, think Polynesian attire. It's the simplest form of clothes out there: just a rectangle of fabric that you wrap around yourself, overlapping a little in the front, and then tightly fold over at the top a couple times to secure it in place. Very lightweight, nice and breezy--you'll probably only sweat at the folded band. Some of us have tried no clothing, but then we're exposed to the sun and the high elevation combined with direct sunlight usually means burns everywhere unless we're very liberal with the sun block, which may not be practical for longer than a week (in which time you can use up two whole bottles with no problem).
For the cold, layers are the key. We do a lot of walking around in the night since the heat isn't beating us down then, and when you have too many warm clothes on, you start to get stifled quickly, so you best not put that winter coat on over that long-sleeved shirt for the trek. But, as soon as you stop, that sweat-covered skin chills super fast and you can be left shivering if you didn't bring something to throw over yourself. My solution was to simply dress in long pants with good socks and shoes (feet are one of the major heat-loss zones, so I really don't recommend going barefoot if you can avoid it when it's cold out), and just a tank top. Even at 45 degrees, as long as you're moving your arms will stay warm enough. When I stop, I untie a heavy sweater from around my waist and throw it on. The great thing about keeping it tied around your waist is that the sleeves get warmed up by being close to your body, so your now-cold arms get an infusion of heat from your hip-heated sleeves. My sister's solution, though, which is better when you have to move fast, is a mechanic's jumpsuit or flight suit over shorts and a tank top. The numerous pockets also allow for packing around a great deal of stuff, including your pocket knife, a first aid kit, extra goggles, a water flask, a flashlight and a bunch more. If she gets too hot, she just has to take her arms out of the sleeves and tie them around her waist. She could let them hang loose since the waist has an elastic band, but I already mentioned the benefits of tying your sleeves around your waist. There are suits out there that also have a double-runner zipper, so if you have to urinate you don't have to strip your top to get yourself out. (And ladies: there's this wonderful product called a Go Girl that can give you the same freedom--just remember to shake it out well before you tuck it back in your pocket or whatever you're carrying it in).
That time of the year, we often see rain, too, if not much. However, last year, on our first day out there, we were hit by a downpour that started suddenly and lasted several hours. The rain caused the ground to be very hard and rough once it dried out, and for anyone who wasn't used to walking around barefoot (we didn't require you to wear shoes if you didn't want to), it would actually cut up their feet. Even those of us who were accustomed to being barefoot had to take good care of our feet by rubbing moisturizer into the cracks each night. It's very important to take care of your feet when they're your only mode of transportation. The ones who wore shoes and socks had to take those off every night to shake the sand out of them, and either moisturize because the sand had dried their feet out or let their feet dry out because they had sweat so much. Again, when your feet are your only mode of transportation, it is imperative that you check on their health every day--sometimes you don't feel the cracks, redness or fungus until it could be too late to treat, or it might take several days of treatment before you're mobile again.
The other major weather we have to deal with is sand-laden windstorms, which can keep you blind to just a few feet for several hours, not to mention getting it into your eyes, nose, mouth, and anything that's not completely sealed (including the inside of your car). Everyone needed some sort of dust mask. My sister and I were quite happy just with our handkerchiefs tied around our faces like train robbers. Protecting the eyes was the less obvious part. Some people just brought sunglasses which admittedly kept their eyes protected from the sun, but offered no protection against the wind. Our solution: welding goggles! They offered protection for our eyes against the wind and kept our eyes shaded. There are also some tinted motorcycling goggles out there as well as clear ones. The clear ones are good for nighttime use, but sandstorms tend to not be as active at night, so only one of our party even bothered with them.
Shelter is an interesting problem in the desert. Because of the wind, most tents can't stay down. There are some dome tents made for high wind that have flexible poles. Not all dome tents will cut it though. Most will be able to handle a week, although some can't, and fewer will be able to handle much longer than a week or two in high winds. And trust me, it's no fun trying to sleep in a tent with a broken fiberglass pole. Other issues tents have are their vents, which will allow in choking amounts of sand in a sandstorm. There are couple solutions to this. Some tents have a decent enough rain fly to keep most of the sand out in a light sandstorm. A better solution is to duct tape a medium-thick blanket over the tent. Better yet, put your tent inside a larger tent with the doors facing opposite directions. That's my favorite solution. I take a dome tent that's just big enough for me to sleep in comfortably and build it inside a tent that has enough clearance to fit it inside (you kind of have to finagle the poles to arrange do so inside another tent, but with the outer tent door open it usually works without problems). A rectangular outer tent works best so that you can walk around the inner tent without too much difficulty. I keep all of my stuff--clothes, etc.--in the outer tent.
This set up also helps with another problem: balancing light and heat. Since we are so much more active in the cool of the night, trying to sleep during the day becomes a bit of an issue because a light colored tent keeps the temperature inside down but lets in a lot more light than anyone is likely to easily sleep in without an eye pillow (which I hate), but a dark one absorbs heat while it keeps the light out. Last year, our outer tent was darker green, keeping the light out of the general structure, and the inside one was red (not as light as it could be) and gray which reflected the heat back into the outer tent. By the time that it got light and warm enough in the inner tent, it was usually mid- to late-morning, which was plenty of sleep if I had gone to sleep at least an hour before sunrise. Another option for shelter in windy conditions is a geodesic dome structure, which are very hardy to windy conditions and keep the dust out nicely if you buy one with an attached floor (or attach one yourself using velcro or duct tape and some tarps), but are not ideal if you have to be able to move quickly because they can take an hour to put up or take down. I still recommend doubling up so you have the combined benefits of light and dark.
Then there's the issue of food when there's no plant or animal sources to forage or hunt. Our group of five got by just fine with a large cooler filled with non-perishable food and no ice. The cooler kept the sand out of our food when it wasn't open. We tried to keep bulk down, so we had a lot of things like noodles, oatmeal, preserved meats (deviled ham and spam, mostly), jerky, dried fruits, cheese and butter powder, powdered milk, and crackers. In the desert, salt is actually very important, because your body needs electrolytes to absorb water. Plus, when you're sweating, you loose a lot of those electrolytes. Tasty foods are also important. When you're hot, you don't feel hungry even when you're working more than normal. I'm a strict three meals and a couple snacks kind of person, but out there, I had to be reminded to eat more than two meals each day, and if they hadn't tasted so good, I wouldn't have eaten very much even then. We did all of our cooking on a propane camp stove. Be warned though: cooking for just 5 people for a week took about 2-1/2 canisters of propane.
Then there is water. You will be amazed how quickly a small group of people can go through water. We brought a whole truck-bed full of cases of water in gallon jugs (each case had four gallons) for our group of four and left with only three cases left. Now admittedly, one of our group was a coffee fiend and was probably responsible for the greater consumption of our water, but even if we didn't count his coffee water, we would have probably used up about 1/2 to 3/4 of that truck load even so. How? Not only do the heat and extra activity of living outside use up extra water, but so does the wind. Wind will dry you out quicker than any other thing--even if you're in the tundra. Sure, we washed, but our washing consisted of wetting a rag down and wiping off what we could, paying special attention to areas like our feet, groins, armpits and faces where moisture was likely to collect--and then dry out, leaving salt behind, which can eventually cause some major discomfort. Some water went to cooking noodles and adding to the powdered foods. The noodle water was usually recycled for washing out our dishes.
Most of the water, though, went directly to drinking. In normal temperatures under lazy conditions, it's recommended that you get 8 cups of water a day (1/2 gallon). One nutrition class I took demonstrated that you could easily get yourself up to recommended hydration standards just by taking a swig of water every 15 minutes. That's not a bad practice. We used that in the desert, taking a swig every once in a while, but adding a good pull any time we felt ourselves being more dehydrated that we wanted to be. The frequency of long pulls was a good indicator of just how much extra water it takes to survive in hot, dry, windy conditions. Don't be surprised if you down a whole gallon or even two just for yourself in that kind of condition.
Even with a schedule of water drinking, you usually don't feel thirsty until that water hits your mouth. If you do feel thirsty, you're already starting to get dehydrated. Cracked lips are another good indicator, especially if they're cracked underneath a good layer of lip balm (which I also recommend when you're in any kind of dry wind, hot or cold--we put it on religiously for snowboarding as well as desert camping--just avoid the tasty ones that make you lick your lips a lot because that defeats the purpose). Other indicators that are very bad signs include dry mouth and gummy eyes (even if you want to deny it by claiming that it's gunk blown in your eyes by the wind). If you or someone in your party is obviously dehydrated, sit them down out of the wind and make them take small sips of water about every five minutes until they start looking better (probably at least an hour). And yes, drinking that much extra water will make you want to urinate a lot, so just remember to keep putting more water and electrolytes back in.
JWR Adds: The currently-approved practice in western armies is to slightly "over-drink", just in case. It is better to be slightly over-hydrated than to risk being under-hydrated.