manufactured by
Camelbak. A human being can survive an average of three to five days without water. Since the human body is composed of an average of 60% water, it should be no surprise that water is higher on the list than food. The need for water dictates that unnecessary water loss by
perspiration should be avoided in survival situations. Perspiration and the need for water increase with exercise. Although human water intake varies greatly depending on factors like age and sex, the average human should drink about 13 cups or 3 liters per day. Many people in survival situations perish due to
dehydration, and/or the debilitating effects of water-borne
pathogens from untreated water. A typical person will lose a minimum of two to four liters of water per day under ordinary conditions, and more in hot, dry, or cold weather. Four to six liters of water or other liquids are generally required each day in the wilderness to avoid dehydration and to keep the body functioning properly. The U.S. Army survival manual does not recommend drinking water only when thirsty, as this leads to inadequate hydration. Instead, water should be consumed at regular intervals. Other groups recommend rationing water through "water discipline." A lack of water causes
dehydration, which may result in
lethargy,
headaches,
dizziness,
confusion, and eventually death. Even mild dehydration reduces
endurance and impairs
concentration, which is dangerous in a survival situation where clear thinking is essential. Dark yellow or brown
urine is a diagnostic indicator of dehydration. To avoid dehydration, a high priority is typically assigned to locating a supply of drinking water and making provisions to render that water as safe as possible. Recent thinking is that boiling or commercial
filters are significantly safer than the use of chemicals, with the exception of
chlorine dioxide. == Food ==