Survival skills
A human being can survive an average of three to five days without the intake of water. The issues presented by the need for water dictate that unnecessary water loss by perspiration be avoided in survival situations. The need for water increases with exercise.
Addax
The addax are amply suited to live in the deep desert under extreme conditions. They can survive without free water almost indefinitely, because they get moisture from their food and dew that condenses on plants. Scientists believe the addax has a special lining in its stomach that stores water in pouches to use in times of dehydration. They also produce highly concentrated urine to conserve water. Pale colour of the coat reflects radiant heat, and the length and density of the coat helps in thermoregulation. In the day the addax huddle together in shaded areas, and in cool nights rest in sand hollows. These practices help in dissipation of body heat and saving water by cooling the body through evaporation.