What happens if you drink more than 8 glasses (64 ounces) of water a day?

Not usually: If you are healthy and active, drinking up to 8-12 8oz glasses daily ina hot climate when sweat and evaporative fluid loss is not unusual. If drinking water during heavy sweating, it's a good idea to mix in some electrolytes, such as a sport drink (diluted) to replace salt loss too. Remember that too much of a good thing can also not be healthy too. Monitor the color of your urine--light yellow.