Geoscience Reference
In-Depth Information
• Your body needs water to digest food. If you have little or no water, limit your intake
of dry foods to the bare minimum.
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In 1984, while climbing El Capitan in Yosemite Valley, we hauled the standard two quarts of water per person per day
for three days of rock climbing. We baked in the sun for three days of a record-breaking heat wave. By the time we
drank our last mouthful of water around noon on day three, we were already severely dehydrated. At times temperat-
ures exceeded 100ºF on the south-facing rock walls, with no shelter or shade. My throat hurt terribly and my mouth and
throat were almost as dry as the back of my hand. Whenever I tried to talk, my tongue would stick like glue to the roof
of my mouth and I would start to gag and retch. By the end of day three, our need for water exceeded our need for rest,
so we climbed into the night, joining forces with the party above us, who had also run out of water. Around midnight,
we reached the top and found a trickle of fresh water feeding a couple of large puddles where we guzzled water to our
heart's content. I can assure you, beyond a shadow of a doubt, if you are as thirsty as we were on that day, you will
drink from the most scummy, disgusting duck pond or ditch water, if that is all you have at hand. Personally, I would feel
terrible if my family had to drink untreated water from a putrid duck pond after a disaster, when I could have planned
ahead and purchased a simple pump-type water-purifying filter from any back-country or surplus supply store.
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Dehydration
Avoid dehydration, because it will sap your body strength, but ration your water usage if you
have a limited supply. Signs of dehydration include thirst, fatigue, dizziness, dry mouth, head-
ache, loss of appetite, dark-colored urine, and sleepiness. If you need physical energy to deal
with your situation, you must do your best to find and conserve water.
Conserving Water
• If traveling in hot country, stay in the shade as much as possible. Avoid midday
travel. Travel at night, if possible.
• Wear loose clothing because it will provide an insulating layer of air, which will help
to reduce evaporative water losses by maintaining high humidity close to the skin.
• Do not go shirtless
.
It will feel cooler, but you will lose more water through evapora-
tion and may sunburn. Severe sunburn can lead to a toxic condition known as “sun
poisoning.”
• Move slowly and avoid overexertion. Try to breathe through the nose—you will lose
less water than by breathing through the mouth.
• Drink in small sips, not big gulps.
• Sucking on a small pebble, twig, or blade of grass can help generate saliva and min-
imize the discomfort of thirst.
• The human body seeks to maintain a certain level of humidity at the skin surface. In
cold, dry climates, this results in the daily loss of significant amounts of water, since
