Thirst

The privation of water is justly ranked among the most dreadful of the miseries of our life… The violence of raving thirst has no parallel in the catalogue of human calamities… Our thirst had become now incessantly more intolerable than our hunger and the quantity then allowed [ 236.59 mls (1 US cups) ] was barely sufficient to keep the mouth in a state of moisture, for about one third of the time… In vain was every expedient tried to relieve the raging fever of the throat… Our suffering during these… days almost exceeded human belief.

~ Owen Chase (1798 1869-03-08 age:70) In the Heart of the Sea Owen Chase was a whaling captain. A huge whale rammed and sank his ship, inspiring the novel Moby Dick.

Having been tortured by water deprivation myself, I concur it is a misery thousands of times worse than you might imagine. I would sooner be eaten alive by tigers than repeat the experience. The Americans in Iraq routinely torture all POWs (Prisoner Of Wars) with water deprivation. They have utterly no idea what cruelty they are imposing. The victim just sits there quietly with no energy to protest.