Water is the world’s most healthy and inexpensive beverage. It can increase energy and endurance, prevent kidney stones, aid digestion, and regulate body temperature. Yet few of us consume as much as we should.

It is surprising how much water your body loses in a day. About two cups are lost just breathing, and another two cups are lost through perspiration just sitting around. Another six cups are lost through kidney and intestinal function. That’s 10 cups you lose just doing office work.

Because foods contain water, you obtain roughly 3 ½ cups of liquid a day through eating. That leaves 6 ½ cups that needs replacement through drinking. The standard recommendation is to drink six to eight cups of water daily. But if you’re doing outdoor activities in the summer heat, you need way more than that.

The U.S. Army developed water consumption guidelines based on air temperature and activity level. When doing easy stuff in lower eighty-degree temperatures you need to be drinking a half quart of water an hour. Hard activity requires three fourths of a quart. Upper eighty temperatures require three fourths of a quart per hour for easy stuff, and a full quart for hard. At temperatures above 90 degrees you need a quart an hour no matter what you’re doing. And by the way, no amount of training or acclimatization can reduce your need for water.

Thirst is not always a good indicator of the body’s need for water, but there are some clinical signs that indicate a need for more water intake. One is constipation, because the intestinal tract is given a lower priority for water than other parts of the body, resulting in hard stools. Dark, brownish yellow urine is also a sign of dehydration for the same reason, indicating the urine is highly concentrated. This can lead to kidney stones and urinary infections. Dry mouth can also result from low water intake. Around 70 percent of your body weight is water, and almost every body function occurs in a liquid medium. So face it, you need water, lots of it.

It’s best to stretch water intake throughout the day. You wake up somewhat dehydrated, so drink a couple of cups first thing in the morning. Don’t drink a lot the first hour after a meal to give your stomach time to digest food undiluted by water.

When you first begin to increase your water intake, you may visit the rest room more frequently at first. Not to worry, you won’t wear out your kidneys, and they will in fact have an easier time functioning. Over time your body adapts and you won’t be going so often. It takes time to learn a new habit, but improving your hydration is a worthy health goal.

Steve Roark is a retired area forester from Tazewell, Tennessee.