The US Centers for Disease Control and Prevention (CDC) urges athletes to take special precautions in hot weather as exercising in extreme heat can make people dehydrated, and get heat-related illness like heat exhaustion or heat stroke, sometimes with fatal consequences. For high school athletes, heat illness during practice or competition is a leading cause of death and disability, yet it is preventable.

The CDC estimates that some 7.5 million American students participate in high school sports every year.

In a statement to the press today, Monday 8 August, Dr Robin Ikeda, CDC’s Deputy Director for Noncommunicable Diseases, Injury and Environmental Health, said:

“Any athlete dying from heat is a tragedy that can be prevented.”

She urged all athletes, parents, coaches and teachers to find out how to recognize and prevent heat-related illness.

Every year, US hospital emergency departments deal with 6,000 visits from people with heat-related illness contracted while playing football, walking, jogging, running, and exercising, say the CDC, who urge people to take the following precautions against illness brought on by heat:

  • If you feel faint or weak, stop and remove yourself to somehwhere cool.

  • Exercise less outside when it is hot, or do it earlier or later when it is cooler, but certainly not in the middle of the day when the sun it at its hottest.

  • Wear lightweight, loose and light-colored clothing.

  • Pace yourself: start slow and increase pace bit by bit.

  • Keep hydrated: drink more water than usual, don’t wait until you are thirsty.

  • Work out with a partner and keep an eye on each other’s condition: get medical help immediately if you or your partner have symptoms of heat-related illness.

Heat Exhaustion is a mild heat-related illness that can develop after several days of being in high temperatures and there is not enough fluid intake to balance the water and salt that the body loses through sweat. People most vulnerable to heat exhaustion include the elderly, those with high blood pressure, and people working or exercising in heat.

The warning signs of heat exhaustion include: heavy sweating; looking pale; muscle cramps; feeling tired, weak or dizzy; nausea or vomiting; and fainting. The person’s skin may feel cool and moist, their pulse will be fast and weak, and their breathing will be fast and shallow. If untreated, this can turn into heat stroke.

You should move the person to a cooler location, make them lie down and loosen their clothing. Apply cool, wet cloths to as much of their body as possible, get them to take small sips of plain water. If they vomit and symptoms don’t improve, get medical attention straight away.

Heat stroke is a serious heat-related illness where the body can’t cool down; it can cause death or permanent disability if emergency treatment is not provided. The body’s temperature rises rapidly (it can reach 106 deg F/41.1 deg C in 10 to 15 minutes) as the body can’t regulate it any more and sweating doesn’t work. The warning signs vary, but usually include: extremely high body temperature; red, hot, moist or dry skin; rapid, strong pulse; throbbing headache; dizziness, nausea, confusion, and maybe unconsciousness.

If you see any of these signs, it is likely that you are dealing with a life-threatening emergency and you need to call 911 immediately while you cool the victim. You should go on a course or undergo instruction from a specialist to find out what to do, but this usually involves getting them into the shade and cooling them as fast as you can by whatever means is at hand, such as immersing them in a cold water bath, placing them under a cold shower or hose spray, sponge them with cold water.

The CDC advises you don’t give them fluids to drink, and call the hospital emergency room for instructions if medical assistance is delayed. Sometimes heat stroke is accompanied by uncontrollable muscle twitching, so just make sure they don’t injure themselves and turn them on their side so vomiting doesn’t block their airway.

The CDC has a web-based course called Heat Related Illness (HRI) Prevention that coaches can take to learn how to protect their athletes from heat-related illness. The course teaches how to recognize, treat and prevent heat-related illness and is also suitable for school nurses and athletic trainers.

There is also a CDC media toolkit aimed at people caring for athletes, as well as vulnerable adults and small children. The kit tells you how to recognize the warning signs of heat illness, and includes information posters for locker rooms, and labels for water bottles, that can be used in schools.

Written by Catharine Paddock, PhD