Don’t rely on thirst to judge if your body is adequately hydrated. Waiting until you’re thirsty to take a drink of water is waiting too long. If you’re drinking around 1 ounce of fluid per pound per day (around 1/2 ounce of just water), plus an additional two or three glasses during times of increased water need, chances are you’re drinking enough. (This amount includes all fluid sources: soups, fruits, milk, etc.) Also, your kidneys can give you a clue. Notice the color of your urine. If your body is low on water, your kidneys try to conserve it by concentrating the urine. If you have enough, or even too much water in your body, the kidneys excrete more water in the urine. If your urine is almost colorless or slightly yellow, you are probably drinking enough liquids. If your urine is darker than usual, like apple juice, drink more water.