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Heatstroke Symptoms: What You Need to Know as Record Heat Waves Approach

Here's how to spot heatstroke and what steps to take.

Jessica Rendall Wellness Writer
Jessica is a writer on the Wellness team with a focus on health news. Before CNET, she worked in local journalism covering public health issues, business and music.
Expertise Medical news, pregnancy topics and health hacks that don't cost money Credentials
  • Added coconut oil to cheap coffee before keto made it cool.
Jessica Rendall
Medically Reviewed
Reviewed by: Troy Mensen, DO
Troy Mensen is a family medicine doctor based in Chicago. He received his Doctor of Osteopathic Medicine from Des Moines University College of Osteopathic Medicine and holds a certification in family medicine from the American Board of Family Medicine. He is licensed by the State of Illinois Medical Examining Board.
Expertise Family medicine, and osteopathic medicine. Credentials
  • American Board of Family Medicine
  • Family Medicine State of Illinois, Medical Examining Board License
  • University of Northern Iowa, BA
  • Des Moines University College of Osteopathic Medicine, DO
3 min read
A reclining woman fans herself with one hand on her forehead
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As some parts of the world experience record-breaking heat waves this summer, it's important to know the right steps to take if you or someone near you starts to experience heatstroke. Heatstroke is the most serious form of heat-related illness, and it happens when your body can no longer control its temperature. If left untreated, heatstroke can lead to organ damage or even death. 

Heatstroke can happen because of overexertion or strenuous activity, but "classic" heatstrokes occur when someone is exposed to a hot environment and their body temperature rises to dangerous levels. Most fatal heat illnesses happen in workers during the first few days of working in warm or hot weather, according to the US Department of Labor, because the body's had no time to acclimate to the increased temperature. 

"It's the kind that we see particularly among the elderly, in very young children, like babies, and when we see these heat waves that go on for several days," says Dr. Korin Hudson, an emergency room physician with MedStar Health.

Here's what to know if you or someone around you starts experiencing symptoms of heatstroke.

Heatstroke symptoms 

Sometimes, heatstroke can start with symptoms of heat exhaustion, which isn't quite as serious as heatstroke, but still requires someone to cool down as quickly as possible. Symptoms of heat exhaustion include nausea, headache, cold skin, a fast or weak pulse and other signs. If left untreated, heat exhaustion can progress to heatstroke, which is a medical emergency. If your symptoms worsen, last more than one hour or you start vomiting, call 911. 

Symptoms of heatstroke, according to the Mayo Clinic and the US Centers for Disease Control and Prevention, include: 

  • Altered mental state, including confusion, agitation and slurred speech 
  • Hot, flushed, usually dry skin (if your heatstroke was brought on by exercise, it may be damp or dry, the Clinic says)
  • Headache
  • Seizures 
  • Very high body temperature (104 degrees Fahrenheit or higher) 
  • Rapid breathing 
  • Racing heart beat
An overflowing glass of water under a running faucet

Keeping hydrated by drinking enough water, both before you head outdoors and while you're out in the heat, is an important step to warding off heat illness. 

Peter Cade/Getty Images

1. Call 911

Having heatstroke is a medical emergency that requires professional care. 

If there's more than one person around to aid the person suffering heatstroke, Hudson advises that one person call 911 while the other helps the victim through the steps below.

2. Get to a cooler area immediately 

If you're around someone who's has heatstroke, move them to a cooler area, such as a nearby air-conditioned room or into the shade. 

Both are good options, but "try to move them out of the heat as quickly as possible," Hudson says. The goal is to cool down the body's core temperature.

3. Take off excess clothing

Removing long sleeves, pants or other clothing will help a person cool down faster. Hudson says the goal is to reach "evaporative cooling," and clothing can prevent evaporation. 

For people who choose to run in layers in order to "sweat off weight," says Hudson, you probably shouldn't. It's dangerous and can lead to heatstroke. 

4. Hold cool towels, ice or water to the skin 

If you have something like a cold towel or water bottle, put it on your or the other person's neck, armpits or groin. But don't give a drink to someone experiencing heatstroke, the CDC says. This might be especially true for people who are confused or who've had a loss of consciousness, according to Hudson.

"Because they have a depressed or altered level of consciousness, it may affect their ability to swallow safely, so it's probably better not to give them anything to eat or drink," she says. 

Check on your neighbors 

Some people are more susceptible to heat illness and heatstroke, such as older adults, younger children, people with mobility issues, certain health conditions and those taking certain medications, including common drugs like blood pressure or antidepressant medications.

In case of a heat wave, be especially mindful to check in with your elderly neighbor down the hall, or a friend who has trouble getting around, according to Hudson.

"This is the time that we really suggest people check on their neighbors," she said. "Especially in places where people don't have access to air conditioning or don't have a way to get someplace cool."

"They may be feeling poorly but can't do anything about it," Hudson added. 

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.