by Richard Wear, M.D.

Most Southern Californians are very much aware of the value of water for our communities. However, it’s easy to forget about the importance of water for our health.

Dehydration can lead to heat exhaustion which can lead to weakness, nausea, faintness, and loss of appetite-all signs that your body does not have enough fluid to carry out its normal functions.

I put this to the test by accident on a backpacking trip with the Boy Scouts. During a long hike on a hot day, I took frequent swigs from my water bottle to replace the fluids I was losing through sweat.

Six hours later, at the end of the trail, I enjoyed a feeling of accomplishment that was quickly replaced by nausea and vomiting. Why? The water I drank on the trail was simply insufficient.

The normal adult loses almost one quart of water every day through just breathing and sweating. There’s also the water lost by the kidney. On the plus side, food adds some fluid into your body.
As a rule, most adults should drink at least 1.5 quarts of fluid every day. If you are doing physical work or exercising you may need 16 ounces of water or more per hour!

A hot environment increases your need for water, as does altitude. If you are visiting the mountains, bring sufficient water-and plan to drink small amounts, more often. Drinking more than eight ounces at a time may slow the progress to the small intestine where the fluid is absorbed.

The ads for beverages like Gatorade promise to replenish electrolytes. Are sports drinks really better than plain water? The answer is…maybe.

While you lose various salts in sweat, urine, and even tears, you also ingest salt (as well as potassium and the other elements in electrolytes) from food. (Don’t count on candy-it’s high in carbohydrates and fat but low in salt.)

However, if you’re exerting yourself in a hot environment for a prolonged period, replace your fluids with a combination of salt and sugar. A commercial sports drink is one way, but another is to make your own electrolyte solution by adding four teaspoons of sugar and a half-teaspoon of table salt to a quart of water. (Flavoring is optional.) Avoid popping salt tablets because they can cause stomach irritation and vomiting.

Another cause of dehydration is traveler’s diarrhea, often caused by contaminated food or beverages. Prevent or treat the resulting dehydration by drinking fluids to replace lost electrolytes. Sports drinks and oft-recommended “clear liquids” contain too much sugar and not enough electrolytes, although they are better than plain water.

The solution from the U.S. Center for Disease Control (CDC) is to drink these do-it-yourself beverages in rotation until you feel better:

• 1 cup of fruit juice (such as apple or orange), with 1/2 teaspoon of honey or corn syrup, and a pinch of salt.
• 1 cup of water with 1/4 teaspoon of baking soda.

For mild dehydration, rice water, fruit juice, or diluted cola drinks may be all you need.
In warmer weather, drink water throughout the day, and increase your water consumption before and during any vigorous activity. If you’ll be traveling, address diarrhea-related dehydration as soon as possible. Enjoy your summer!

Dr. Wear practices Internal Medicine at HMF and is certified in Advance Wilderness Life Support