Bushcraft and Survival Skills

Desert Survival

I must stress having plenty of spares and enough water for everyone in case of a breakdown in the back country. With today's modern transportation, it's quite a simple thing to get stranded 45 miles from nowhere and no water. Make sure you've got a few gallons of it before you go.

1) Control loss of body fluids. Urinate as little as possible. Save it for when it can be recycled through a solar still. Don't depend on them to provide your party with water. In optimim conditions, a solar still can provide a pint or two of water a day, not adequate by any means to keep one alive.) Diarhhea in a temperate climate can quickly lead to death by dehydration. Avoid alcohol, which contributes to dehydration, and any diuretics such as coffee and caffeinated sodas.

2) Avoid Sweating. Control your level of perspiration as much as possible. This means avoiding the sun. Stay in the shade. Save shelter construction, water collection, and all other tasks for night time if possible. Construct a bed that keeps you off the ground and allows air to circulate under you if possible. Do not lie on the ground. Try to keep fully clothed as clothing holds the sweat in so it will evaporate slower, cooling the body and decreasing perspiration. You may feel cooler without a shirt, but will perspire more and also risk a debilitating and dehydrating painful sunburn. It gets cold in the desert at night, sometimes, uncomfortably cold. During the day, I'd try to sack out on something that circulates air underneath me, but at night, I'd look for insulation. Some of this depends on the time of year and good ole common sense. Use what you have.)

3) Avoid Smoking. Smoking tobacco will dry the throat and add to your thirst.

4) Suck on a pebble. It's an "old Indian trick" but it works. Sucking on a pebble helps produce saliva, keeping your mouth moist and diminishing the sensation of thirst.

5) Avoid Salt Water. Should you find yourself on a coastline do not drink the sea water. Recycle it through a solar still. Have several solar stills. One is not nearly enough.

6) Do not drink Urine. This would obviously be a last resort, but it will only cause you more problems as your kidneys attempt to process waste products you are re-introducing to the body. The more dehydrated you are the more toxic your urine will be. Recycle it through a solar still. Drinking alcohol, salt water, blood, and urine will only increase the effects of dehydration. Water that is more than 50% salt will increase dehydration while that which is less than 50% contaminated will increase the body's relative water content.

7) Eat Sparingly. Digestion requires water. Proteins require more water than complex carbohydrates, starches, and sugars. Raw fruits and vegetation contain greater water content than many processed foods. Avoid salty foods. I've often seen middle eastern people eating melons, especially watermelon, in the desert setting. This idea has alot of merit to it.

Watermelon has a pronounced diuretic effect. Perhaps the Middle Easterners have a genetic or acquired resistance to it.

The "avoid salty foods" does lessen your may reduce thirst, but are continuously losing essential salts [electrolytes] in sweat, so don't avoid salt so much that tip over into salt-depletion heat exhaustion. [Very similar symptoms to water depletion. Get very thirsty, but no amount of water will quench the thirst and will even make it worse.

8) Breathe through your nose and limit talking.

9) Avoid rationing. If you attempt to ration water at the rate of one or two quarts a day you will not avoid dehydration any longer than if you drank a full gallon. Although you might psychlogically alleviate thirst, in high temperatures your body will still dehydrate at a constant rate. Perspiration should be rationed. (Which means to ration physical activity) 50% salt solution by weight would be roughly 500 grams sodium chloride per litre [1000 ml] water, which is close enough to 1000 grams of water. Water won't dissolve this much salt. A saturated solution of sodium chloride [ "salt"] in water would be 265 grams salt in 1000 grams of water, or 26.5% solution. Any more added salt would sit on the bottom, undissolved. And certainly wouldn't want to drink a 26.5% solution, Unless had taken a poison and wanted to induce instant vomiting.

Decades ago the advice was to "ration" water to small sips. No real advantage in doing this in most cases. As dehydration increases, the ability to think clearly decreases. Better to try to stay reasonably alert than try to ration water and stumble past water sources in a daze.

Depending on heat and humidity, "rationing physical activity" can mean "no activity in any possible shade".

"Though the material that gives seawater its salty flavor is composed of many substances, sodium chloride, or common salt, is by far the predominant compound. On the assumption that 1 gallon (about 4 litres) of seawater contains 0.231 pound (about 105 grams) of salt and that rock salt on the average is 2.17 times as dense as water, it has been estimated that if the oceans of the world were completely dried up they would yield at least 4.5 million cubic miles of rock salt, or about 14.5 times the bulk of the entire continent of Europe above the high-water mark. Seawater contains on the average about 3 percent salt, although the actual concentration varies from about 1 percent (in the polar seas) to 5 percent. Enclosed waters such as the Mediterranean and Red seas contain a higher proportion of salt than does the open ocean at the same latitude. Irrespective of the source of the seawater, salt obtained by the evaporation of

seawater has the following composition:

• sodium chloride 77.76 percent
• magnesium chloride 10.88 percent
• magnesium sulfate 4.74 percent
• calcium sulfate 3.60 percent
• potassium chloride 2.46 percent
• magnesium bromide 0.22 percent
• calcium carbonate 0.34 percent

Suppose the sea water had a lower salt concentration from a large inflowing river, tropical storm, etc. At what level of salt would it be worthwhile drinking? I would hate to guess, personally. Both the magnesium chloride and magnesium sulfate are used as cathartic effects and are used as purgatives. [extreme laxatives] Which means if you drank much of it you would get extreme diarrhoea which would empty the stomach and intestines of both food and fluid, leaving you worse off. Sea water would be fine for solar stills, though.

You need more than one or two. If warm and sunny enough to make the stills work well, the survivor will probably be dehydrating faster than the stills produce water. Thin plastic is OK for solar stills, is lightweight and cheap, has other uses.

Dehydration the loss of water from the body; it is almost invariably associated with some loss of salt (sodium chloride) as well. The treatment of any form of dehydration, therefore, requires not only the replacement of the water lost from the body but also the restoration of the normal concentration of salt within the body fluid.

Dehydration may be caused by restriction of water intake or by excessive water loss. The commonest cause of dehydration is failure to drink liquids. The deprivation of water is far more serious than the deprivation of food. The average person loses approximately 2.5 percent of total body water per day (about 1,200 milliliters [1.25 quarts]) in urine, in expired air, by insensible perspiration, and from the gastrointestinal tract. If, in addition to this loss, the loss through perspiration is greatly increased--as is demonstrated in the case of the shipwrecked sailor in tropical seas or the traveler lost in the desert--within only a few hours the dehydration may result in shock and death. When swallowing is difficult in extremely ill persons, or when people cannot respond to a sense of thirst because of age or illness or dulling of consciousness, the failure to compensate for the daily loss of body water will rapidly result in dehydration and its consequences. "

IMHO, this is info is far more accurate than the over-optimistic advice in some survival books and manuals, especially the military ones. It is quite possible to die within hours if try to walk around in the sun. Perhaps this is due to fact that insolation is higher in southern hemisphere than northern. [less population, lower pollution, much more heat from sun reaching ground per unit area] Leave a steel crowbar on the ground here for 20 minutes in summer and can be too hot to pick up with bare hands.