2005 Year in Review

Water Can Help Prevent Heat Exhaustion and Heat Stroke

Source: Martha J. Winter, Extension Educator, Nutrition and Wellness, mjwinter@uiuc.edu

Water is the beverage of choice for the body. In fact, losing more than 10 percent of your body weight from dehydration can cause heat stroke. And a 20 percent water loss can cause death. Water is truly the beverage of life.

"Each day, our body loses about 8 to 10 cups of water through sweat, urine, exhaled air and bowel movements," explains Martha Winter, nutrition and wellness educator with University of Illinois Extension. "That means you need to drink about 8 to 12 glasses of water each day."

If you exercise, you lose more water and thus need more. Getting enough water is especially important for older people. The older you are, the more vulnerable you become to dehydration. Dehydration is one of the most frequent causes of hospitalization among people over 65.

And, water is critical when the weather is hot because it helps control our body temperature.

What About Heat Exhaustion and Heat Stroke?

We assume that our thirst mechanism will protect us from dehydration. But this is not always the case. Winter says that it is possible to lose fluid so quickly that the normal thirst mechanism is overwhelmed or overridden.

On average, we lose 2½ quarts (about 10 cups) of fluid just from our daily activities. This loss is generally replaced by the fluid we drink and the food we eat. But exercise, sweating, diarrhea, outdoor temperature or altitude can significantly increase the amount of fluid required. The most common cause of increased fluid loss is exercise and sweating.

In the hot summer, heat exhaustion and heat stroke are possible.

Heat exhaustion is not life threatening and is characterized by fatigue, nausea, lightheadedness and possibly heat cramps. Heat exhaustion usually comes on several hours after exertion and dehydration. With enough rest and water, heat exhaustion is self-correcting. To prevent heat exhaustion, consume enough water while you are exercising. Drink because you know you should, not because you feel thirsty.

Heat stroke, on the other hand, is a life-threatening emergency. Winter says that without proper care, heat stroke victims will most likely die. When the body's core temperature rises, the brain, which can only function in a very narrow temperature range, begins to fail. In an effort to cool the blood and lower the core temperature, the brain will dilate all the blood vessels in the skin. As a result, the skin becomes red and hot, but may be either wet or dry. As the brain overheats, the individual may become disoriented, combative, argumentative, and may hallucinate wildly. If heat stroke occurs, seek medical attention immediately.

"To prevent both heat exhaustion and heat stroke, stay well hydrated," says Winter. "Of course, plain water is the most obvious choice. Most sport drinks would also be a good choice. But, avoid alcoholic beverages."

by  Editor, theCity1.com
August 2, 2005