Water basics, the effects of dehydration, how and when to drink it.
It is an understatement to say water is crucial to life. Water is life. You will die if you don’t drink water within two or three days. Even cutting back causes distress. “Lack of water is always the most severe privation that men can be condemned to endure,” wrote Ernest Shackleton. The need is greater in hot climates, where the body loses water more rapidly through perspiration. Physical activity, altitude, stress, and illness or injury also hasten the loss of water and its need for replacement. But even sitting quietly in a shelter in Arctic cold, you must drink at least 2.3 liters—more than half a gallon—each day to replace the water you lose and to function efficiently.
If you lack water, conserve your energy. Don’t smoke or drink alcohol. In a hot climate, exert yourself only at night. Also try breathing through your nose and eating only a minimum. Without water, the human body rapidly deteriorates. Blood becomes thicker, making the heart work harder to pump it. Impaired circulation reduces the ability to shed excess heat in hot climates or retain heat in cold ones. As dehydration increases, the body pulls water from cells to keep blood flowing, which damages cell membranes and increases cellular salt concentrations.
Your biggest challenge may be finding water that’s clean enough to drink. Most of the Earth’s surface is covered with undrinkable saltwater, and most of the rest—stored in ponds, lakes, streams, and rivers—is contaminated with microorganisms and chemicals. You will need to develop water-purification skills to survive in the wild. But what if you have no means to purify water you collect in the wilderness? You may have to weigh your options. Going without water threatens life. So too may the illnesses caused by drinking impure water. You may decide to drink, and survive, in the short run and deal with any life-threatening illnesses later.
The standard recommendation is to figure one gallon of water per person per day for wilderness consumption. That’s also the amount recommended for storage for home emergencies. Desert conditions require more water. Each person venturing in the wild should carry as much water as is comfortable, along with a purifying device if no fresh water is available.
Carrying as much water as you need for extended trips is impossible. Besides being bulky, each gallon weighs about eight pounds, making the aggregate unwieldy. Thus, long-distance hikers as well as people in survival situations must know how to find, store, and purify water.
For short trips, water can be carried in a variety of containers. Metal vacuum flasks are almost unbreakable but can be heavy when filled. Plastic bottles are lightweight and tough but may melt if left too close to a fire.
Pouches clipped to the belt or worn on the back allow water to be easily accessed while keeping hands free.
Large plastic water bags can be hung from trees for use in a large camp. Water bladders such as polypropylene Platypus containers or CamelBaks (place in backpack, drink through tube) are nearly weightless and collapse flat when empty.
EFFECTS OF DEHYDRATION
Losing up to five percent of body fluids causes thirst, weakness, nausea, and irritability. Pulse increases, and skin may become flushed. Judgment may be seriously impaired even if the body loses only two percent of its fluids.
Losing up to ten percent causes headaches, dizziness, and tingling in limbs. Sufferers may lose the ability to walk and speak clearly. Skin may turn blue, and vision may begin to blur.
Loss of 15 percent severely impairs vision and hearing, swells the tongue, and makes urination painful. Sufferers may be unable to swallow, or may exhibit signs of delirium.
Loss of more than 15 percent usually causes death.
Many signs of dehydration match common physical symptoms of fear and panic. When the two are combined, they strike the body doubly hard.
HOW AND WHEN TO DRINK
It’s best to take small drinks at regular intervals, such as every hour, to prevent dehydration.
Look for obvious signs of dehydration in yourself and your companions: dark, sunken eyes; dark, smelly urine; fatigue; and shriveled skin. Begin drinking immediately.
The optimal drink for someone who already is dehydrated is plain water. Salts and minerals in sports drinks can interfere with the body’s absorption of water.
Don’t wait to become thirsty before you start drinking or looking for water. A noticeable thirst begins when the body is two percent dehydrated. It’s difficult to drink more than a quart of water at one time without experiencing discomfort; therefore, once serious dehydration begins, it may take hours to return your body to a healthy state.