Terry Schuchany prefers to exercise indoors these days, especially after a frightening episode on a hot tennis court nearly killed her. Schuchany has been a runner and in good shape all her life. She is used to working out in the heat. So, on a sweltering August day, she prepared for tennis by drinking plenty of water before and during play. She remembers asking her husband to call an ambulance, but does not remember being taken to the emergency room at Baylor Medical Center Dallas, where she was later diagnosed with hyponatremia. It's a condition that occurs from over-hydration.