Through the remainder of the summer, as our athletes are preparing for the upcoming seasons to begin and the temperatures are rising, it is a good time to look at exertional heat illness.
According to the Centers for Disease Control and Prevention, heat illness during practice or competition is the leading cause of death among high school athletes. It is also preventable. You must know the signs and symptoms of heat illness and take actions accordingly.
When doing activity in the heat, you must become acclimatized to the heat before enduring high levels of exertion. It takes seven to 14 days to acclimate to the heat. During this acclimation period, activities should be gradually increased in intensity and duration.
As an athletic trainer on site at early practices, we are constantly checking temperature and humidity using wet bulb global temperature (WBGT) measurements to determine if it is safe to participate outdoors or if equipment should or should not be worn based on the WBGT. If you do not have access to a WBGT device, there are some weather apps available for your phone that give you the estimated WBGT in your area.
You can use a heat index chart that can be found on numerous websites, including NOAA. The difference is that heat index is measured in the shade; WBGT is measured in the sun and takes into account sun exposure, temperature, humidity and wind. If you know the temperature and humidity, which can be found on any weather app that most of us have on our phones, you can have general idea if it is safe to be outdoors and what your risk of heat illness may be.
The first stage of heat illness is usually heat cramps when working out. Cramps occur in the larger muscles – usually in the legs. This is due to dehydration and fatigue. These cramps can be relieved by stretching and massaging the muscle. You need to replenish fluids, and I would recommend drinking a sport drink that includes sodium.
As heat illness progresses, you may experience heat exhaustion. With this you might experience fainting or near fainting, dizziness, tunnel vision, nausea and/or vomiting. If you experience these symptoms, you need to find a cool area. Find an area of shade if you can’t get indoors, but ideally go indoors in a climate controlled environment so you can cool your body and replenish fluids.
As symptoms increase, there may be some central nervous system dysfunction. This can include confusion, disorientation or hallucinations. Anyone who begins to show these symptoms must be cooled. Use a cold tub and submerge the person to the head. If this is not available, use ice packs on key areas, including neck, armpits, groin and behind knees, or wrap the person in cold towels. Call EMS and monitor vital signs.
Exertional Heat Stroke occurs when the core body temperature reaches 105 degrees or higher. As the core body temperature rises, more central nervous system dysfunction occurs. Some of these signs include staggering, unusual behavior, delirium, aggressiveness, apathy, collapse and finally unconsciousness. This person needs immediate body cooling and medical attention.
To prevent heat illness, know the heat stress of your area. Hydrate before, during and after outdoor activity. During activity it is recommended to consume six to 10 ounces of water or sport drink for every 15 minutes of exercise. Post activity, you will need to replenish fluids as well. Drink at least 12 ounces of fluids for every pound of body weight lost during exercises due to sweat. Avoid outdoor exercise in the hottest times of the day; usually this is 10 a.m. to 5 p.m. Know your hydration levels. You can tell your hydration based on urine color. Ideal color is light yellow, like lemonade. Dark urine indicates dehydration.
Most importantly, if heat stroke is suspected, make sure you cool the person before you transport to the local hospital. Cooling can prevent death. Be safe and know your risk prior to doing any outdoor activity. The following links are handouts that might be helpful in reminding you of symptoms and what do to in the event of heat illness.