Heat Illness in Outdoor Sports: When Minutes Matter
By Orthopedic Surgeon James Slauterbeck, MD
It has been an incredibly hot summer in North Carolina and across much of the country. We are all excited about watching our young athletes compete outdoors, whether they are playing football, soccer, lacrosse, field hockey, tennis, running cross-country, or training for other outdoor sports. Sometimes we think the biggest risk they face is the opponent across the field or the next big race. But at this time of year, the biggest risk to athletes on both teams may actually be the heat.
Our bodies normally protect us by releasing heat into the surrounding environment, especially through sweating. The biggest concern comes when the body becomes unable to get rid of heat as quickly as it is being produced. Hot, damp conditions make this especially difficult. When humidity is high, sweat does not evaporate as effectively, and the body has a harder time cooling itself. As an athlete’s core temperature continues to rise, heat illness can become increasingly severe.
Heat illness exists on a spectrum. It can begin with relatively minor problems such as heat rash and progress to heat cramps, fainting (heat syncope), heat exhaustion, and finally exertional heat stroke. Heat exhaustion may cause weakness, nausea, headache, dizziness, thirst, and muscle aches, but mental status remains normal. Once an overheated athlete becomes confused, combative, uncoordinated, has a seizure, or simply seems “not right,” heat stroke should be suspected. A core temperature above 104°F combined with altered mental status defines this medical emergency.
All outdoor athletes are at risk, but some face greater danger than others. Athletes who wear heavy or protective equipment, such as football players in full pads, lacrosse and field hockey players with helmets and pads, and catchers or goalkeepers in protective gear, are at higher risk because this equipment traps heat and interferes with the evaporation of sweat. Larger athletes are also more vulnerable; their lower surface-area-to-mass ratio makes it more difficult to release stored heat. One study of 22 Georgia high schools found that football linemen had roughly 2.5 to 3 times the risk of heat syncope or heat exhaustion compared with backs and specialists, and similar principles apply to larger athletes in other sports.
Prevention starts with heat acclimatization. Athletes should gradually become accustomed to exercising in the heat over 7 to 14 days, with protective equipment added progressively rather than all at once. Practice times should be adjusted, when possible, to cooler parts of the day. Hydration should also be individualized because some large athletes can lose more than 3 liters of sweat per hour. Regular fluid breaks, monitoring body weight changes, and educating athletes and coaches about drinking according to conditions are key components of safe training.
When more severe heat injury occurs, the most important message is simple: cool first, transport second. Rapid cooling should begin on the field rather than waiting until the athlete reaches the hospital. A systematic review of 521 people with exertional heat stroke found 100% survival among those cooled rapidly, compared with 84 percent survival when cooling occurred more slowly. Cold- or ice-water immersion is the preferred treatment because water removes body heat rapidly. The goal is to reduce core temperature to approximately 102 degrees Fahrenheit, ideally within 30 minutes of athlete collapse. If a tub is unavailable, continuously pouring or spraying cold water over the athlete and applying ice-water–soaked towels to areas like the neck, armpits, and groin can help, along with moving the athlete to shade or an air-conditioned environment if possible.
Heat stroke is preventable and treatable when people recognize it and act quickly. Every outdoor practice field, track, or court where athletes train in the summer heat should have a cooling plan, access to a tub or other immersion setup, ice, cold water, and trained staff ready before the first whistle or starting gun.
When an overheated athlete’s mental status changes and core body temperature increases, minutes matter. Recognize it, cool immediately, and then transport.
James Slauterbeck, MD, is an orthopedic surgeon whose special interests include sports medicine, adolescent sports medicine, female sports medicine, and high school and college athletic injuries. He is affiliated with UNC Health Orthopedics at Southeastern Health Park and UNC Health Southeastern. To learn more, call (910) 738-1065 or visit https://www.unchealth.org/care-services/doctors/s/james-r-slauterbeck-md.
