The month of August brings the beginning of another school year.

For many student-athletes, the fall semester starts several weeks before their first class. Football, soccer, cross country, volleyball, tennis and golf all begin their respective seasons during one of the hottest months of the year.

Just as the students adjust to life back in the classroom, so must their bodies adjust to the demands of sports in hot temperatures.

Ailments related to the heat can pose a serious health risk to athletes. In fact, these conditions are the third most common cause of death in athletes behind cardiac disorders and neck trauma.

Unfortunately, many athletes and coaches are unaware of the seriousness of these conditions.

Korey Stringer, an offensive lineman for the National Football League’s Minnesota Vikings, died from heat stroke suffered during a preseason practice in August 2001. Several years later, in October 2007, the Chicago Marathon was canceled prior to all participants crossing the finish line due to dangerous conditions with high temperatures and humidity that resulted in one death and 49 hospitalizations. These tragic incidents grabbed national headlines, but helped increase efforts to improve education and prevention programs for all heat-related illnesses.

Exercise results in the production of heat, which must be released to keep the body’s temperature at a normal 98.6F. Normally, this temperature is maintained through sweating, the body’s natural cooling system. However, for athletes who perform strenuous activity in hot and humid environments, sweating is less effective and the body temperature can rise. After prolonged exposure to these harsh conditions and continued sweating, the body becomes dehydrated and its temperature continues to rise. Under these conditions, the symptoms of heat-related illnesses are most likely to occur.

Heat-related illnesses vary in degree from mild to severe, with the most severe form being potentially fatal. Early symptoms include thirst, leg swelling, light-headedness or dizziness and generalized weakness. Most of these ailments are temporary, and easily remedied with hydration and rest in a cool location.

Prolonged exposure to hot and humid conditions, along with limited rest and water intake, may result in more severe symptoms. Heat cramps are painful spasms or muscle cramps of the thigh, calf, arm and abdominal musculature. The complete inability to exercise because of heat-related symptoms is referred to as heat exhaustion, and is associated with headaches, nausea, vomiting and malaise.

Both conditions can be adequately treated with hydration and prolonged rest, but they also can be warning signs for more dangerous conditions that require immediate medical attention.

Progression or continued symptoms despite treatment can lead to heat stroke, a life-threatening condition defined by a body temperature greater than 104F along with mental status changes, including irrational behavior, emotional instability, altered consciousness, collapse and coma.

Most heat-related illnesses commonly occur during the first few days of practice and with the introduction of protective equipment.

Each athlete must adapt to the heat and attain an appropriate fitness level for the sport being played to prevent heat illness.

Most sporting organization bodies, including the Illinois High School Association, National Collegiate Athletic Association and National Football League, have guidelines regarding preseason practice to allow athletes to become acclimated to the weather safely.

Essentially, over the first two weeks of the preseason, a gradual increase in exertion, environmental exposure time and equipment wear is allowed to give the athletes a chance to gain fitness and heat tolerance.

Dehydrated athletes are more likely to suffer from heat-related illnesses. Unfortunately, many athletes do not realize they are becoming dehydrated, either due to lack of education or intense concentration on their sport. Thus, coaches, athletic trainers and parents may need to intervene to ensure appropriate hydration.

Different sports organizations offer specific guidelines as to the amount of fluid needed. Nonetheless, the drinking of water or a sports drink should be encouraged throughout practice and throughout the day. In addition, the athlete should develop good hydration practices, including monitoring their body weight before and after practice, as well as checking their urine color.

Athletes should never lose more than 2 percent of their body weight during a practice, and their urine color should be clear to light yellow.

Heat-related illnesses are a set of preventable conditions common in the month of August as athletes start practice for the fall season. Through proper education of coaches and athletes, a gradual initiation to practice, concentration on hydration and appropriate monitoring of athletes with any heat-related symptoms, more serious conditions can be avoided.

Dr. Leonard specializes in shoulder reconstruction, arthroscopy and sports medicine and is affiliated with Christ Medical Center. In addition to his clinical practice, he is the team physician for Carl Sandburg High School, Marist High School, Windy City Magic Basketball and American Hearing Impaired Hockey Association. He traveled to Finland in March to cover the USA AHIHA Olympic Games.