 Keep listening for more entertaining and informative opinions from Judge Jeanine Fierro. This is House Call for Health. As heat waves sweep through the country, one expert weighs in on water consumption and how important it is to stay hydrated. Emergency physician and clinical associate Dr. Liana Nguyen says the 8 by 8 rule, which is 8 8-ounce glasses of water or 64 ounces each day, is a good rule of thumb when trying to determine how much to drink.