This is the time of year doctors like me worry about heat exhaustion and heat stroke and the importance of maintaining hydration to prevent serious heat related illnesses. Exertional heat stroke is the third leading cause of death among high school athletes and is often related to inadequate preparation for exercise in the heat. Heat exhaustion occurs when the core body temperature is elevated between 100.4 - 104 degrees. This is a different problem than having a fever. If the body becomes overheated during outdoor exercise exhaustion symptoms may occur. Look for signs of muscle cramps, fatigue, thirst, nausea, vomiting and headaches. The skin is usually cool and moist secondary to sweating and indicates that the body's cooling system is at work. When you become overheated breathing becomes fast and shallow and the pulse is rapid. These are all signs that you need to stop your activity. It is important to move to a cooler area and begin rehydration immediately. The best prevention for heat related illness is prevention. Your kids need to hydrate BEFORE beginning any extended activity in the heat. Begin drinking fluids the night before and maintain continuous hydration while exercising. Take frequent breaks and try to move to the shade while drinking fluids. You need to drink fluids even when you're not thirsty. If you're thirsty, you are already behind in your fluid intake. With good education and recognition of the early signs of overheating heat related illnesses are preventable. I'm Dr. Sue with TKD, helping parents take charge.