Dehydration Dangers—What you need to know before the summer heat takes its toll on your body

August 2013 View more

N2013_08_01_006HEALTWith summer heat in full swing this month, don’t let dehydration slow you down. Our bodies contain about two thirds water. You need to replenish those lost fluids more often when you’re out and moving during the heat of the day. Dehydration occurs when you lose more fluids than you take in. This can be especially serious for both the very young and the very old. Losing large amounts of water can especially be dangerous to your health.


On an extremely hot and humid day, it can feel much hotter to your body than the actual air temperature reads. The heat index measures how hot it really feels on your body when humidity levels are factored in with the air temperature. On many summer days we can end up with feels-like temperatures of 100 degrees or more. It’s important to note that heat index values were devised for shady conditions with light winds. Full sun exposure can increase heat indices by up to 15 degrees Fahrenheit. The combination of very hot dry air and strong winds can be particularly hazardous to your health. During heat waves—a prolonged period of excessive heat, often combined with excessive humidity—it is important to routinely check on neighbors, especially the elderly or those that do not have air conditioning. During the infamous Chicago heat wave of 1995, more than 700 people died in their homes from heat exposure.


On a steamy, hot day, it’s more difficult for your body to cool itself naturally. When too much fluid is lost through sweating, your body temperature rises and heat illnesses can develop. There are mild, moderate, and severe levels of dehydration, depending on how much of the body’s fluid is lost and not replenished. When it becomes severe, dehydration can quickly become a life-threatening emergency. “Warning signs of dehydration and heat stroke include lethargy, dizziness, fast-beating heart, nausea and a dry mouth. Take these symptoms seriously. Heat stroke can eventually lead to seizures, coma, and death,” said Dr. Thomas Scaletta, medical director, Edward Hospital Emergency Department. When seriously dehydrated, you also lose electrolytes, the mineral compounds, like salt, which are necessary to maintain a healthy fluid balance and regulate body temperature. Sometimes the situation can become dangerous. “If someone is in poor physical shape, not acclimatized to the heat, a small child, an elder, or has serious medical illness, they can get into trouble very fast,” said Dr. Scaletta.

A simple way to determine whether you are hydrated is simply by the color of your urine. It should be pale yellow. A dark color means that your kidneys are working too hard to concentrate the urine. You need more fluids.


During extreme heat, limit your time outdoors to 15-minute intervals. “Drink lots and lots of fluids, especially sports drinks. Avoid alcohol and caffeine, especially hyper-caffeinated ‘energy’ drinks, as both are diuretics and increase fluid loss,” said Dr. Scaletta. Periodically misting yourself, and especially your small children, is a great way to cool off.

August is also a time when mandatory workouts tend to be in full swing for middle and high school fall sports. Make sure you supply your child with plenty of water so they can drink before, during, and after practices. “Let your coach know if you are struggling,” said Dr. Scaletta.

Thousands of runners are also banking their miles this month as they train for Naperville’s first marathon on November 10. Dr. Scaletta recommends you dial it back on extremely hot and humid days and find the shady routes. “Wear light-colored, loose, synthetic clothing that will evaporate sweat,” said Dr. Scaletta.