Off Duty, Military Health and Fitness - Marine Corps Times

Drink up as summer temps heat up

Drinking enough water seems intuitive, but when it becomes an afterthought, people exercising or working outdoors can become dehydrated without knowing it.

With schools out and vacations planned, more troops and their families are heading outdoors. But experts warn that many of them will change exercise habits without giving their bodies the time or resources to catch up.

“If you’re not acclimatized to new environmental conditions and you’re increasing your duration or intensity of exercise, you’re at a greater risk of dehydration, one that can even occur over a three- to five-day period,” said Brendon McDermott, an athletic trainer at the University of Connecticut.

The warning signs include thirst and fatigue, but McDermott said the process begins as soon as the body’s water level starts to decrease. When temperatures start to climb, a person can become dehydrated after 30 minutes, depending on his weight and exercise intensity level, said Dr. Michael Sawka of the U.S. Army Research Institute of Environmental Medicine.

“This causes a reduced exercise performance, maybe a reduced cognitive performance and, likely, a greater susceptibility to heat illnesses,” Sawka said.

Of these illnesses, heat exhaustion is the least serious, Sawka said, associated with moderate or high temperatures and accompanied by hot skin and dehydration. Heatstroke is more serious; it damages the central nervous system and is marked by confusion, impaired judgment and seizures or blackouts.

Sawka said heat injury falls in between. It can impede function of the liver, kidney, gut or muscles, and it is characterized by dizziness, fainting and blood or tissue damage.

A drop in body weight, a darker-colored urine and thirst are all dehydration indicators.