Preventing heat injuries Published July 17, 2009 By Maj. Darryn Bryant 19th Aerospace Medical Squadron aerospace and operational physiology flight commander LITTLE ROCK AIR FORCE BASE, Ark. -- Second in a three part series Heat exhaustion is a condition caused by water and electrolyte loss. The primary cause of symptoms is related to the amount of sodium chloride (salt) lost. Symptoms can include excessive thirst, fatigue, exhaustion, nausea, muscle cramps, anxiety, agitation and headache. If treatment is further delayed, a heat stroke may result. Heat stroke is a potentially life-threatening situation. Death can occur in less than 30 minutes. As the brain overheats, the person may become disoriented, combative, argumentative and may hallucinate. Symptoms may also include seizures, vomiting and comas. We assume our sense of thirst will protect us from dehydration. This isn't always the case. Our thirst sensation doesn't normally kick in until we are already 2 percent dehydrated. Don't wait until you feel thirsty to drink -- it may be too late. Instead, design a fluid plan, just like you plan what you will be eating that day. Drink a couple of glasses of water with breakfast, throughout the morning, lunch, mid-afternoon then some more at dinner. A good rule of thumb is drink at least 72 ounces of fluid every day. Obviously, if you're exercising or working outdoors and sweating a great deal, you'll need much more fluids than the basic recommendation. The type of fluid isn't nearly as important as the overall quantity, although water should be your first choice. But beware that alcohol and caffeinated beverages are both diuretics, which can increase fluid loss. Here are some tips to protect yourself from heat injuries: Stay well hydrated by drinking fluids beginning about 12 hours before a scheduled work or exercise period. Our bodies can lose up to 2.5 quarts per hour, but can only absorb about one quart of water per hour. Carry a clean, reusable water bottle at work, especially if you typically spend a lot of time outdoors. Pay attention to work and rest cycles and take frequent breaks from the outdoor heat. If possible, wear clothing that allows evaporation to help with the cooling process. Supervisors also need to pay close attention to where their people are and what they're doing when they are working in the heat. Everyone should be able to recognize the early signs and symptoms of heat illness, so further progression can be avoided. For more information regarding heat injuries, contact the aerospace and operational physiology flight at 987-7389.