By Vicki Rackner, M.D.

On Health

Summer heat places you at risk for dehydration. Even a mild imbalance of water can cause serious medical problems.

According to the Centers for Disease Control and Prevention, more Americans die of extreme heat exposure than from hurricanes, lightning, tornadoes, floods and earthquakes combined.

Preventing dehydration is your best and safest strategy.

Your body has an optimal fluid balance. As with your checking account, you stay in balance by putting in the same amount you take out. When it’s hot or it’s humid or you’re exercising, your body cools itself by sweating. Sweating results in a withdrawal from your body’s “water bank,” so you need to drink more to stay in water balance.

You’re in water balance if you’re not thirsty, right? WRONG! Thirst is not a reliable gauge of your body’s needs, especially in children and the elderly. The color of your urine is a much more reliable indicator of your water balance. If you’re well-hydrated, your urine is clear or light-colored; if you’re dehydrated your urine is dark yellow or amber.

Here are some tips for staying in fluid balance:

? Remind yourself to drink regularly even if you’re not thirsty. Remind your parents and your kids. Better yet, ask your kids to remind you and their grandparents to drink.

? Choose your fluids wisely. In general, water is the best drink. You can add a slice of lemon or lime. Alcohol and caffeine tend to have a diuretic effect, which means that they cause a net withdrawal from the fluid bank rather than a deposit.

? Stay cool. Go to the air-conditioned library and enjoy the many resources there.

Know the signs of dehydration

The earliest signs include fatigue, weakness, and poor concentration. Headache, dizziness and fainting are associated with even mild dehydration.

Check with your doctor if you’re on diuretics or “water pills” or fluid restrictions.

Never leave anyone in a closed parked car.

Dr. Vicki Rackner is author of a “Chicken Soup for the Soul Healthy Living Series.”