Released: May 09, 2003
Heat, Humidity Got You Down? Add Fluids to Keep Cool, Protect Health
MANHATTAN, Kan. – Summer heat and humidity increase the risks of dehydration. Anyone can be susceptible, and some may increase their risks unknowingly, said Sandy Procter, registered dietitian and K-State Research and Extension nutrition specialist.
Children can be particularly vulnerable – they may become preoccupied with play to the point where they forget to stop for a drink of water. They’re not alone, she said.
"Teens and adults who may be working outside or enjoying recreational activities also may skip recommended breaks. Even older adults who may – or may not – be active can be at risk because the senses – including thirst – decline with age," Procter said.
When a person senses thirst, he or she has reached the first stage of dehydration; after thirst, comes fatigue, and weakness. Delirium and death can follow.
Dehydration is a preventable health risk, she said.
Drinking six to eight 8-oz. glasses of water each day is a basic recommendation for health. The need to increase fluid replacement increases in warm weather and at times of heightened activity. Health professionals recommend drinking water before and after physical activity, and taking frequent breaks to replenish fluids. On humid days, when perspiration isn’t likely to evaporate as quickly as it does on drier days, additional fluids are needed.
Water is preferred as a ‘replacement’ fluid; it is naturally occurring and easily absorbed, Procter said.
Fifty-five to 75 percent of an adult’s body is water. When more water is needed to cool the body (through perspiration or "sweat’), there will be less fluid available for other essential functions, including transporting nutrients; cushioning bones, joints and skin; and eliminating wastes, she said.
Some replacement fluids may come from other sources, including fruits and vegetables that have a high water content. Lettuce, for example, is about 95 percent water by weight; a raw tomato is about 93 percent water; and watermelon is about 92 percent water.
Milk also can be a good choice – it has a high water content (about 89 percent) and is a good source of calcium that is necessary for bone health.
Beverages with caffeine such as coffee, tea and some carbonated beverages, are slightly dehydrating by nature and should not be used as fluid replacements. The same is true for alcoholic beverages – alcohol acts as a diuretic, Procter said.
Carbonated beverages should not be considered as primary sources of fluid replacement, either. They are not absorbed as easily as water and may contribute little, if any, nutritional value, the nutrition specialist said.
Sports drinks, which are formulated to replace lost electrolytes (sodium; chloride and potassium) needed for an athlete’s recovery, can be helpful during prolonged activity of 45 minutes or more. The fact that sports drinks are "in" can be an inducement for children participating in organized activities to replace fluids, yet the importance of water should not be overlooked; water still is the most natural way in which to replenish essential fluids quickly, Procter said.
Carrying a water bottle in a belt pack or shoulder sling has become popular with walkers, runners and others who spend time outdoors. Refillable bottles with different colored lids also can be helpful to families or groups (like a camp group) needing to replace fluids on the go. And, while keeping a thermal container filled with water handy during outdoor activities is recommended, carrying one in the car or truck also can be a life-saver, she said.
For more information on fluid replacement, nutrition and health, contact the local K-State Research and Extension office or visit http://www.ksre.ksu.edu and click on "Health and Nutrition."
K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.
Sandy Procter is at 785-532-1675