Heat exhaustion progresses slowly, and this might be the first clue.
Tragically, heat exhaustion is the leading cause of death and disability among high school athletes in the United States, according to the Centers for Disease Control and Prevention. Nearly 10,000 high school athletes experience heat exhaustion during practice or competition every year.
The intensity of football practice in late August underneath layers of padding and gear obviously increases the risk of heat exhaustion and heat stroke, but heat exhaustion can happen to anyone. Between 1999 and 2010, almost 8,100 Americans died of a heat-related illness, and about 70 percent of those occured in adults over 65 years old, according to the CDC.
What Is Heat Exhaustion?
Heat-related illnesses occur on a spectrum. Symptoms may begin subtly at first and seem harmless, become more severe, and potentially end with fatal consequences.
The body has specific mechanisms for cooling off. In hot and humid temperatures, your body sweats, which cools you off as if you are misting your skin with a spray bottle. Your cardiovascular system also adjusts, expanding blood vessels in your skin to allow greater blood flow.
But your body’s thermoregulation has a limit and—unfortunately— many people don’t recognize the early signs of heat exhaustion and do not take action to prevent heat stroke, the last stage of heat exhaustion. During heat stroke, body temperature may exceed 106 degrees Fahrenheit within minutes and requires immediate medical attention.
The First Signs of Heat Stroke
One warning sign that many people, especially athletes, tend to ignore is heat cramps. A heat cramp is a muscle spasm that usually happens in your abdomen, arms, and legs during heavy exercise, especially under hot temperatures.
Of course, “heavy exercise” can have a different meaning to different people. Someone who is older, out of shape, or has problems with their heart may experience heat cramps even during light exercise on a hot day.
Runners and other athletes often shrug off muscle spasms as a “charley horse,” but all muscle cramps can be a sign of trouble. (Here are other reasons you keep getting charley horses.) A heat cramp on a hot day is a warning sign that heat exhaustion may be on its way, and your body is in danger.
If heat exhaustion progresses, you may notice heavy sweating and extreme thirst. These are clear signs that your body is becoming dehydrated under the blazing sun and you need a break.
What to Do During Heat Exhaustion
“Pushing through” early stages of dehydration and heat exhaustion is a slippery slope. The condition can worsen quickly. If you notice heat cramps or other signs of dehydration, take these actions immediately:
Seek shade or an air-conditioned room
Take off any excess clothing, like jackets or sweaters or socks
If feeling weak or dizzy, lie down
Get medical help if symptoms last more than an hour
It’s no fun to step away from a tied game, or to leave the beach early, but heading to the ER is worse. Don’t let the sun cramp your health: Take a break.
Want more summer health tips?
Charkoudian N. Mechanisms and modifiers of reflex induced cutaneous vasodilation and vasoconstriction in humans. J Appl Physiol. 2010 Oct;109(4):1221-8.
Extreme heat. Washington, DC: U.S. Department of Homeland Security. (Accessed on June 13, 2018 at https://www.ready.gov/heat.)
Heat emergencies. Washington, DC: U.S. National Library of Medicine. (Accessed on June 13, 2018 at https://medlineplus.gov/ency/article/000056.htm)
Heat illness. Washington, DC: U.S. National Library of Medicine. (Accessed on June 13, 2018 at https://medlineplus.gov/heatillness.html.)
Heat illness among high school athletes —- United States, 2005--2009. Atlanta, GA: Centers for Disease Control and Prevention, 2010. (Accessed on June 13, 2018 at https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5932a1.htm.)
Heat-related illness. Atlanta, GA: Centers for Disease Control and Prevention. (Accessed on June 13, 2018 at https://www.cdc.gov/pictureofamerica/pdfs/picture_of_america_heat-related_illness.pdf.)
Severe nonexertional hyperthermia (classic heat stroke) in adults. Waltham, MA: UpToDate, (Accessed on June 13, 2018 at https://www.uptodate.com/contents/severe-nonexertional-hyperthermia-classic-heat-stroke-in-adults.)
Why do I sweat so much? Jacksonville, FL: Nemours Foundation. (Accessed on June 13, 2018 at https://kidshealth.org/en/teens/sweat.html.)