Feature Story

Health Center Today, August 11, 2010

Summer Heat Poses Potential Health Dangers for Athletes Training for Fall Sports

By Carolyn Pennington

The weather may still be hot and steamy but high school and college athletes are gearing up for the fall season. When you are active outdoors in this type of weather you need to be alert for signs of heat injury, ranging from mild heat cramps to life-threatening heat stroke.

In recent years, several professional and college athletes have died from heat stroke which occurs when the body temperature increases too much, causing stress on the body that may harm tissues. Between 1995 and 2007, there were 31 deaths in the United States due to heat injury in high school football alone.

"When we exercise, our bodies cool off by sweating," explains Dr. Peter Schulman, cardiologist with the Pat and Jim Calhoun Cardiology Center. "As we perspire, we lose necessary body fluids. If we do not replace these fluids, we become dehydrated. This makes it difficult to sweat and cool down, which can result in a heat injury."

During regular exercise, 70 to 90 percent of the energy our bodies produce is released by heat. Many factors can hinder heat release and perspiration. These include:

Environment. Air temperature, combined with humidity, wind speed, and sun affect how well our bodies cool themselves. Humidity influences how easily sweat can evaporate. High humidity (greater than 60%) makes sweat evaporation very difficult.
Clothing. Dark clothing absorbs heat. This can dramatically increase the chance of heat stress. Full body clothing, heavy pads, and helmets make cooling more difficult.
Sun exposure. Direct exposure to the sun with no available shade can increase your core body temperature.
Fitness level/acclimatization. Before exercising in the heat, athletes must be in good physical condition. They also need to give their bodies time to adjust to warmer temperatures.
Age. Children adjust to heat more slowly than adults. Their bodies are less effective at regulating body heat.
High body fat. Athletes with high body fat have greater difficulty cooling themselves.
Medications. Diuretics and stimulants may increase risk.

Headache, nausea, seizures, and confusion or disorientation often occur with heat stroke. Unconsciousness and coma are possible. Heat stroke may occur with no preceding signs of heat injury.

"It’s important for young athletes to be educated about the warning signs of heat injury," says Schulman. "Don’t be macho, be prudent and tell your coach if you’re not feeling well."