No predictor can assure how quickly dehydration will kill someone. Health, weather and individual physical activity levels can help determine how long a person will survive without water.
Biologists from George Washington University in Washington, DC, Randall Packer say, in a very hot environment, adults can lose between 1 and 1.5 liters (2.1 to 3.2 liters) in one hour’s sweat.
“A child left in a hot car or athlete who is working hard in hot weather can experience dehydration, an environment that is too hot and dies within a few hours,” he said.
Usually, when a person experiences dehydration, he or she is suffering from heat, or that the internal temperature is too high.
But, this case is not always the case, especially among certain groups of people, says Dr. Kurt Dickson, a doctor at Banner Thunderbird Medical Center in Arizona. Children and parents suffering from dementia may not remember to drink water, or even get their own water without help.
According to the 2009 National Health Service guide in England, severe dehydration occurs when one loses about 10 percent of their total weight. But losing 1.5 liters of water loss per hour on a hot day, can make dehydration faster.
Symptoms typical of dehydration
As soon as one’s water level down there are some typical symptoms that arise: thirst, dry skin, fatigue, dizziness, confusion, dry mouth, and rapid pulse.
Children who experience dehydration can even cry without dripping tears. Their eyes, cheeks and stomach became concave.
Dr. Jeffrey Berns of the National Kidney Foundation in the United States said that when water levels drop in the body, fluid in the body is transferred to fill vital organs through blood, causing cells to shrink throughout the body.
As water comes out of brain cells, Berns explains, the brain and blood vessels inside the skull can break, as reported by LiveScience.