In the experiment, participants underwent plenty of physical activity in the heat without drinking or eating anything. The dehydrated volunteers were unable to concentrate during tests that were either tedious or oriented on details.
Georgia Institute of Technology (Georgia Tech) researcher Mindy Millard-Stafford identified attention, coordination, and complex problem solving as the brain functions that were most affected by dehydration. Meanwhile, brain activities associated with fast and simple reaction time tasks didn't experience anywhere near the same level of disruption, even when dehydration got worse.
One of the co-authors of the study, Millard-Stafford warned that dehydration diminishes attention and other cognitive abilities. Dehydrated people will experience difficulty in accomplishing jobs that require attention, such as paying attention throughout an important but long meeting, driving a car over long distances when it is hot, or working in the overheated conditions of a factory. (Related: Drink more water: This simple and holistic advice is the best way to optimize urological health.)
Millard-Stafford and her colleagues drew their data from peer-reviewed research papers on dehydration. They evaluated the participants' scores in attention, executive function, motor coordination, and speed of reaction to tasks.
They found that participants committed an increasing number of mistakes as their dehydration grew worse. In particular, participants performed the worst during boring and repetitive activities.
Next, the Georgia Tech researchers combed through research papers on the dehydration-related loss of body mass. They determined that the worst effects on cognitive functions began to appear once the body lost two percent of its weight in water, a loss that could take place in a surprisingly short amount of time.
The earliest symptoms of dehydration include dizziness, headaches, nausea, and thirst. Another early indicator is the appearance of heat cramps, where the loss of large amounts of salt and water cause muscles to spasm uncontrollably. If dehydration is not halted or treated properly, it can lead to an extended stay in the emergency department of a hospital.
Older people are highly vulnerable to dehydration. They are much less capable of sensing thirst and lose more fluid during urination due to their weaker ability to concentrate urine.
Infants and young children also need to be kept hydrated. They have a lower total body weight, a greater concentration of water, and a more rapid metabolism that uses up electrolytes and water at a faster rate.
The best way to beat dehydration is to stay hydrated. Hydration should also be performed with care. A person who drinks excessive amounts of water dilutes the concentration of salt and sodium in his or her blood. This unhealthy state is called hyponatremia, and it can trigger seizures and cause brain tissues to swell.
Taking a proactive approach is important to maintaining hydration and health. Consume the right amounts of food and water, respectively.
Physical exercise and other intense activities should be performed during the cooler and darker periods before sunrise or after sunset to avoid too much exposure to heat. People can limit the loss of heat during those cooler periods by wearing light-colored clothing and a hat.
Health experts reiterate that heatstroke is a medical emergency. If a person begins displaying symptoms of heatstroke, experts advise calling for medical assistance so that the patient can be quickly cooled at an emergency department.