July 2011 - Navy
By Captain Kathryn M. Serbin

The weather is changing and as the temperature and humidity rises, so do the risks associated with sun and heat exposure. Dehydration and heat stroke are two common heat-related illnesses that can be life-threatening if left untreated. Children, older adults over the age of 60 and individuals who have chronic medical conditions are particularly susceptible to dehydration.

We usually lose body fluids through sweat, and other bodily functions. Healthy people replace the loss of fluids by drinking and eating foods that contain water. However, when individuals are ill, they can become dehydrated rather quickly. Sometimes, dehydration can occur when using prescribed medications or weight loss drugs, such as diuretics, which deplete body fluids and electrolytes. The most common symptoms of dehydration may include: thirst, decreased or less-frequent urination, dry skin, fatigue, light-headedness, dizziness, confusion, dry mouth, and increased heart rate. In children, additional symptoms may include: dry mouth and tongue, no tears when crying, lack of urination for more than 3 hours, high fever, listlessness and/or irritability. Whatever the cause, dehydration should be treated as soon as possible.

In cases of mild dehydration, rehydration is possible by simply drinking fluids. Many sports drinks on the market effectively restore body fluids and electrolytes. In children, directions for giving food and fluids will differ according to the cause of the dehydration, so it is important to talk to your pediatrician. For adults and children, moderate to more severe cases of dehydration require immediate medical assistance with possible hospitalization.

There are steps you can take to prevent dehydration, such as drinking eight to ten glasses of water a day, especially when working or playing in the sun. If you are planning to be out in the heat, start drinking a couple of hours before you head out so that you are well hydrated and, then, make sure you drink at regular intervals throughout the activity. If you must be out in the heat, make sure you have enough water or sports drinks on hand in a cooler.

Heat stroke is the most severe form of heat illness and is a life-threatening emergency. It is the result of long, extreme exposure to the sun, in which a person does not sweat enough to lower body temperature. Our bodies produce our own amount of internal heat and we normally cool ourselves by sweating and radiating heat through the skin. However, in some circumstances, such as extreme temperatures, high humidity or vigorous activity in the hot sun, this cooling system may begin to fail, allowing heat to build up to dangerous levels. If a person becomes dehydrated and is unable to sweat enough to cool his/her body, his/her internal temperature may rise to dangerously high levels, causing heat stroke. The most common symptoms of heat stroke, although each individual may experience symptoms differently, may include: headache, dizziness, disorientation, agitation or confusion, sluggishness or fatigue, seizure, hot, dry skin that is flushed but not sweaty, high body temperature, loss of consciousness, rapid heartbeat and hallucinations.

There are some immediate first aid measures you can take while waiting for help to arrive: get the person indoors if possible, remove clothing and gently apply cool water to the skin followed by fanning to stimulate sweating, apply ice packs to the groin and armpits.

There are precautions that can help protect you while you work and play to prevent the negative effects of heat and sun exposure. Remember to drink plenty of fluids and avoid caffeinated beverages and alcohol as these can lead to dehydration. Wear loose fitting clothing in light colors and wear a hat, sunscreen and sunglasses. Try to schedule vigorous activity and sports for cooler times of the day and find shady spots in which to rest. Acclimate yourself to the change in temperature by gradually increasing the time spent outdoors to get your body used to the heat. While outdoors, break for a drink even if you do not feel thirsty; by the time you start to feel thirsty, you are already dehydrated! Mist yourself with a spray bottle, hose or take a dip into the nearest pool of water to avoid becoming overheated. Plan indoor activities on very hot and humid days. Planning ahead, staying hydrated and keeping cool are important reminders to ensure you can enjoy the summer months ahead!

The author, Captain Kathryn M. Serbin, BSN, MS, CCM, is a Reserve Nurse Corps, Mental Health Specialty Leader.