Heat Illness

What is heat illness?

            Heat illness is a preventable sports injury that occurs in hot or humid weather.  The body’s ability to cool itself becomes overwhelmed and the body overheats. 

Are there different types of heat illnesses?

            Yes, heat illness covers heat cramps, heat exhaustion, and heat stroke.  Heat cramps are most common in athletes.  Although heat stroke is less common, it may be fatal. 

What causes heat illness?

            During exercise, an athlete’s body produces heat causing his or her temperature to rise.  Normally, the body has the ability to cool itself by sweating.  As sweat evaporates, it cools the skin.  When the weather is too hot or humid, sweating may no longer cool the athlete enough to keep his or her temperature below dangerous levels.  Once the temperature has gone above 104 ºF, the body can lose its ability to cool itself making the situation even worse. 

            Dehydration is also a risk for heat illness.  Exercising in hot, humid weather can cause dehydration in as little as 30 minutes.  Unfortunately, thirst is not a good measure of hydration status or fluid needs.  The thirst mechanism will not kick in until an athlete has lost 2% of body weight as sweat.

            Other risk factors include heavy equipment or clothing, recent illness or fever, obesity, deconditioning, certain medicines, chronic diseases, alcohol or other drugs, and eating disorders.

What are the symptoms?

            The symptoms of heat illness progress from mild (heat cramps) to life threatening (heat stroke) as the body loses its ability to cool down.  Recognizing the mild symptoms early can help prevent problems that are more serious.

            Heat Cramps:  symptoms include painful muscle spasms- most commonly in legs, arms or abdominal muscles.  

            Heat Exhaustion:  symptoms include nausea and vomiting, fatigue, headache, dizziness, weakness, muscle aches, chills, and increased sweating

            Heat Stroke:  is a life-threatening condition in which the body’s temperature rapidly rises to 104 ºF or higher.  Heat stroke may damage the kidneys, heart, lungs, muscles, liver, intestines, and brain.  Symptoms include NO sweating, confusion, dizziness, agitation, strange behavior, seizures, and coma.

How are they treated?

            Heat Cramps:  rest, stretching and massaging the cramped muscles, and drinking plenty of fluids.  Sports drinks to replace salt and other electrolytes are preferred over water.      

            Heat Exhaustion:  Stop all activity, rest in a cool shaded area with the legs elevated.  Remove excessive equipment and clothing.  Rehydrate with frequent small amounts of fluid.  If unable to tolerate small sips, IV fluids will probably be necessary.

            Heat Stroke:  Call 911.  Emergency medical treatment is necessary to treat heat stroke.  Rapid cooling is required- remove unnecessary clothing, immerse in ice water, wrap with cool wet towels, or cool the body with ice packs.

When can an athlete return to play after heat illness?

            An athlete that suffers from heat cramps can return to competition after rehydrating and the cramps stop.  A player that experiences heat exhaustion should not return to activity for at least 24 hours or more.  A person who has heat stroke should avoid exercise for at least 1 week and needs clearance by a physician before returning to activity.

How can an athlete prevent heat illness?

            It is important for an athlete to allow his or her body to adapt to the hot weather.  Gradual increases in workout intensity and duration over a 10 to 14 day period will help.  Avoiding the hottest part of the day by exercising early in the morning or later in the evening can also help. 

Drinking plenty of fluids including sports drinks and water will help prevent dehydration.  An athlete can weigh before and after practice to monitor his or her fluid status.  Any weight lost is due to sweat and should be replaced by fluids to prevent further problems.  Some athletes lose more salt in their sweat than others do.  For them, it is important to replace salt losses throughout the day to prevent cramping. 

It is also important to wear loose fitting, light colored clothes to promote heat loss.  Maintain proper nutrition, avoid alcohol or drugs, and stay in the shade as much as possible.