Summer Health Concerns for Kids

Kleiner explains that you lose about 4 cups of water per hour of exercise, depending on how much you weigh and how much -- and how quickly -- you perspire. A moderate workout in a mild climate will likely result in a loss of 1 to 2 quarts of fluid per hour through perspiration. The more intense the exercise or the more extreme the temperatures, the greater the fluid loss.

“If you don’t replenish your fluid losses during exercise, you will fatigue early, and your performance will be diminished,” says Kleiner. “If you don’t replenish fluid after exercise, your performance on successive days will decay, and your long-term health may be at risk.”

According to the National Athletic Trainers’ Association, says Kleiner, dehydration can impair your physical performance after less than an hour of exercise -- even sooner if you start working out in a dehydrated state. It can also increase your risk of developing symptoms of heat illness, such as heat cramps, heat exhaustion, and heat stroke.

Not Just for Athletes

It’s not just athletes -- even the weekend variety -- who are dehydrated, says Jacob Teitelbaum, MD, author of "From Fatigued to Fantastic!: A Manual for Moving Beyond Chronic Fatigue and Fibromyalgia."

For even the sedentary he suggests: “Simply occasionally pay attention to your mouth and lips. If they are dry, you’re thirsty and need more water.”

Dehydration can be a serious problem for anyone, but children and older adults are at greater risk, according to the Gatorade Sports Science Institute. It offers these tips to avoid dehydration:

--When exercising, drink early and often. Research shows exercise under warm or hot and humid conditions can cause dehydration in as little as 30 minutes. So it’s important to consume fluids not only during and after exercise, but also before a workout or strenuous activity.

--Don’t wait until you’re dehydrated to start drinking. Drinking in a dehydrated state can cause gastrointestinal distress.

--The American College of Sports Medicine recommends that athletes drink enough fluid to fully replace sweat losses during their activity. At a minimum, drink 8 to 10 ounces of fluid every 15 minutes during exercise.

--When active, don’t rely on your sense of thirst. When you are hot and sweaty, your thirst mechanism can shut off quickly and you may not realize you need fluids.

--Drink on a schedule.

--Check the color of your urine. If your urine looks like the color of apple juice, you are probably dehydrated. If it looks more like the color of lemonade, you are probably well hydrated.