Your body deals with excessive heat by sweating — relaxing the pores in your skin to allow water to escape, reducing temperature through evaporation. When you work outside for long hours and are exposed to constant heat, your body is under a lot of stress. As long as your body has enough water to produce sweat and cool itself, it can keep running smoothly. If you don’t drink enough fluids, however, your built-in cooling system can get confused and stop functioning in an attempt to conserve fluids for other functions. If your body is deprived of fluids for too long a time it will stop producing sweat to regulate body temperature. When that happens, your core body temperature can rise quickly.  This condition is what we call heat exhaustion. The lack of sweat is the first tell-tale sign; if you suddenly stop sweating in hot conditions, you need to get out of the sun quickly. As heat exhaustion progresses, other symptoms may follow, including nausea, dizziness, abruptly feeling tired, clammy skin and a rapid heartbeat. If getting into the shade isn’t enough to stop these symptoms, lay down in a cool place. Loosen any tight clothing, put your feet up and drink cool water. You may consider spraying yourself down with cool water or lying down in front of a fan. A cool bath may help. If your symptoms prevent you from moving, stay where other people can see you. If your body temperature goes over 104, you might run the risk of a seizure, heatstroke and possibly a heart attack. To avoid heat exhaustion there are a few precautions you can follow. Don’t wait until you’re overheated to drink water. Carry a bottle with you and drink constantly to keep yourself hydrated. Always move to a cool, well air-conditioned area when taking a break from your outdoor activity. Alcohol and caffeine can cause you to overheat more easily, so avoid them if you are going to be in the sun for hours. For something tastier than water, carry juice-sweetened drinks. Wearing loose clothing will allow your body to cool more efficiently.