Heat Exhaustion vs. Heat Stroke: What’s the Difference?

Kenneth Knowles, MD
Medically reviewed by Kenneth Knowles, MDJuly 21st, 2020
How Does Dehydration Affect the Body

Summer is finally here! As you sweat your days away in the blistering heat, dehydration is not the only lurking ailment that you should be wary of—especially if you are committed to actively enjoying these warmer months outside. Heat exhaustion and heat stroke are two other potentially serious conditions that can wreak havoc on your summer plans if left unchecked, making it important to understand the differences between these conditions and their relative symptoms. In this article, we’ll walk you through the symptoms of heat exhaustion and heat stroke—stressing the importance of understanding these heat-related illnesses, their differences, and how to prevent them.

A Trick of the Heat

Wait, aren’t heat exhaustion and heat stroke the same thing? While both conditions are classified as heat-related illnesses and show similar symptoms, heat stroke is much more serious than heat exhaustion.

Heat-related illnesses are often triggered in hot, humid environments where the body can’t keep itself cool. As your body temperature rises in this setting and dehydration onsets, the natural cooling agent for your body—aka sweat—is suppressed. Once this happens, the likelihood of heat exhaustion and exacerbations like heat stroke escalates. Let’s take a closer look at the differences between these two heat-related illnesses.

Heat Exhaustion

Heat exhaustion is a heat-related syndrome with symptoms that typically include a lot of sweating and a rapid pulse. Heat exhaustion can occur during strenuous outdoor activities or with prolonged exposure to extreme heat and high humidity. Without prompt medical treatment, heat exhaustion can worsen into heat stroke—an exacerbation that can become life-threatening if not treated.


Thankfully, heat exhaustion is preventable and, if caught early enough, can be treated. Symptoms of heat exhaustion range from mild to severe and can develop suddenly or over time. Common indicators of heat exhaustion include:

  • Cool, moist skin with goosebumps despite being in the heat
  • Heavy sweating
  • Dizziness
  • Fatigue
  • Extreme thirst
  • Vomiting
  • Dark urine
  • Weak, rapid pulse
  • Headache, body aches, and muscle cramps
  • Nausea

Heat Stroke

Heat stroke is a common exacerbation of heat exhaustion, where the body overheats due to prolonged exposure to or exercise in high temperatures. This is one of the most dangerous forms of heat illness, occurring when your body temperature elevates above 103 F (39.4 C). Heat stroke does require prompt emergency treatment, as an untreated heat stroke can quickly cause vital organ damage. The longer treatment is delayed, the worse these damages can be—increasing your risk of serious complications or death.


Warning signs of heat stroke can include those aforementioned symptoms of heat exhaustion, as well as:

  • Warm, dry skin (i.e., you’ve stopped sweating)
  • Confusion and/or altered mental status

Risk Factors & Prevention

The CDC warns that roughly 600 people in the United States die from complications related to extreme heat every year. While no one is immune to the effects of brutal heat, complications of heat illnesses can be more dangerous to at-risk individuals. Those at greater risk include children under the age of four and adults age 65 or older. Younger children’s bodies haven’t fully developed the ability to self-regulate temperature and older adults can have weakened systems due to medications or an aged body. Certain chronic illnesses, like COPD and congestive heart failure, can also increase the risk of heat stroke.

Fortunately, heat-related deaths and illnesses are preventable. In order to react swiftly and appropriately in response to heat exhaustion and heat stroke, especially for at-risk individuals, it’s important to identify the warning signs and take proper precautions. Some prevention tips that you should take this summer to avoid falling victim to heat-related illnesses include:

  • Staying hydrated
  • Wearing loose, breathable clothing when venturing outside
  • Protecting against sunburn
  • Avoiding sitting in a parked car midday
  • Avoiding exerting yourself on extremely hot days

How DispatchHealth Can Help


Of course, even if you take preventive measures while outside on those brutally hot days, heat exhaustion can still occur. If you believe that your heat exhaustion has escalated into heat stroke or if you are at higher risk of developing complications from heat-related illnesses, DispatchHealth is prepared to offer you the prompt, at-home medical care that you need. We have become one of the most dependable house call services for acute medical conditions, arriving at your place of need with most of the equipment and technologies found at an ER. Reach out today to learn more or save our number to speed dial for your next emergency. Requesting care is as easy as contacting us via phone, mobile app, or through our website.


DispatchHealth relies only on authoritative sources, including medical associations, research institutions, and peer-reviewed medical studies.

Sources referenced in this article:

  1. https://www.accuweather.com/en/weather-news/heat-exhaustion-vs-heatstroke-what-are-the-warning-signs-and-how-should-you-react/347987
  2. https://www.healthline.com/health/heat-stroke-vs-heat-exhaustion
  3. https://www.franciscanhealth.org/news-and-events/news/heat-exhaustion-or-heat-stroke-infographic
  4. https://www.uhhospitals.org/Healthy-at-UH/articles/2019/07/heat-stroke-vs-heat-exhaustion-what-you-need-to-know
  5. https://www.mayoclinic.org/diseases-conditions/heat-stroke/symptoms-causes/syc-20353581
The DispatchHealth blog provides tips, tricks and advice for improving lives through convenient, comfortable healthcare.

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