average of 60% water, it should be no surprise that water is higher on the list than fire or 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 the human water intake varies greatly depending on factors like age and gender, 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 Culinary root tubers, fruit, edible mushrooms, edible nuts, edible beans, edible cereals or edible leaves, edible cacti, ants and algae can be gathered and, if needed, prepared (mostly by boiling). With the exception of leaves, these foods are relatively high in calories, providing some energy to the body. Plants are some of the easiest food sources to find in the jungle, forest or desert because they are stationary and can thus be obtained without exerting much effort. Animal trapping, hunting, and fishing allow a survivalist to acquire high-calorie meat, but require certain skills and equipment (such as bows, snares, and nets). Focusing on survival until rescued, the Boy Scouts of America especially discourages foraging for wild foods on the grounds, as