WATER

Minimum water, salt, and carbohydrate needs in survival settings have been carefully studied. Results show that a person can survive an initial period by drinking as little as 1 litre of fluid per day under the most ideal conditions, but 1.5 litres or more of fluid is preferable. At first, a minimum goal should be 2 litres of water for every person. If the climate is hot, the ration should be increased to 3 or 4 litres. If the weather is very hot or the living conditions are hot and humid such as may occur in shelter confinement, there may be considerable sweating. Under these conditions, 4 or 5 litres of water per person might be necessary to prevent dehydration. 

These water rations are only for drinking or cooking-water for personal hygienic needs is not included. 5 Infants, children, nursing mothers, and persons doing heavy physical work might need more fluids. Persons with illnesses resulting in greater than normal water losses would need extra fluids also. The Food and Agriculture Organization recommendation is 9 litres/day per person for drinking and hand washing.