Heatstroke is a life threatening medical emergency. It’s usually caused by being outdoors in extremely hot and humid weather, but it can also be caused by being in overheated indoor spaces.
Heatstroke is the most serious type of heat injury that can occur. It’s caused by overheating of the body to a core temperature of 104°F (40°C) or higher.
There are two types of heatstroke:
- Exertional heatstroke: This type of heatstroke is often caused by intense physical exertion that takes place outdoors during hot weather.
- Nonexertional (classic) heatstroke: This type of heatstroke often affects older adults and people with chronic, underlying health conditions such as diabetes. Classic heatstroke may come on gradually over the course of several hours or days.
When not treated promptly, heatstroke can cause serious damage to the internal organs of the body, including the brain. Untreated heatstroke can also be fatal.
Read on to learn the symptoms and causes of heatstroke as well as prevention strategies and treatments.
Heatstroke symptoms may come on rapidly or slowly. Heatstroke is always a medical emergency.
Adults older than 65 and infants are particularly vulnerable to heatstroke. So are people who exercise or have physically demanding jobs that take place outdoors in hot, humid weather. However, anyone can get heatstroke, so it’s important to know the symptoms.
Symptoms of heatstroke include:
- running a high fever (skin feels hot to the touch)
- excessive sweating or dry skin that doesn’t sweat (anhidrosis)
- muscle cramps
- rapid pulse and heart rate
- low blood pressure
- rapid breathing
- loss of balance
- irrational or erratic behavior
- nausea and vomiting
- dehydration (dry mouth and intense thirst)
- low urine output or dark urine
- physical collapse
Symptoms of heatstroke in babies and kids
Infants and small babies lack the ability to effectively regulate body temperature.
Heatstroke can escalate into a medical emergency very quickly in babies and young children. Symptoms in children and babies may include:
- fever of 103°F (39.4°C) or higher
- loss of consciousness
- hot, dry, or sweating skin
- red, flushed-looking skin
- rapid pulse or heart rate
- shallow breathing
- lethargy or sluggishness
Look for immediate medical attention if you suspect heatstroke in your child, especially if they’ve been in a high-heat environment
Heatstroke is usually brought about by being in an environment that’s very hot and humid. Drinking alcohol, not drinking enough water, or wearing heavy or dark clothing in a hot environment may increase your risk.
While not a cause, age can be a risk factor. It’s more difficult for babies and adults older than 65 to regulate internal body temperature. This may make people in these age groups more prone to heatstroke should overheating occur.
In older adults, heatstroke may be more likely to occur in overheated indoor areas than outdoors. Visiting cooling centers or installing fans and air conditioning can help you avoid this scenario.
Heatstroke is a medical emergency that always requires immediate assistance and treatment.
If a baby or small child has heatstroke symptoms and is found in an environment such as a hot, airless room or hot car, call 911 or local emergency services or bring them to an emergency facility immediately.
Heatstroke symptoms may also be a sign of a less-severe heat-related illness such as heat exhaustion. It can be hard to know what condition you or the afflicted individual is experiencing. For that reason, always look for immediate medical help for symptoms that may indicate heatstroke.
If you or someone else is experiencing heatstroke symptoms, do what you can to bring down body temperature while waiting for emergency medical aid. Things to try include:
- moving out of the heat into an air-conditioned room or shaded area
- removing excess clothing
- immersing your body in an ice bath or cold-water bath
- if cold-water immersion isn’t possible, applying cold compresses to the groin, back of neck, forehead, and armpits
- if you’re conscious and can hold down fluid, drinking cool or cold water or sucking on ice chips
Medical evaluation and treatment should still be looked for, even if you feel better after taking these steps.
Heatstroke is typically diagnosed through a physical examination and assessment of symptoms. If heatstroke is suspected or diagnosed,
Once you receive a diagnosis, medical treatment that’s designed to bring down your core body temperature will be given. A healthcare professional may use various techniques to lower your temperature such as:
- cold-water immersion
- evaporative cooling, which uses misted water and blowing air
- cooling blankets
- ice packs
- cooled-down intravenous (IV) fluids
- cold-water lavage (catheters containing cold water are inserted into the rectum or throat)
Cooling the body down is essential for lowering the risk of complications from heatstroke such as heart, brain, or kidney damage. If you’ve lost consciousness, cooling will continue during resuscitation.
During the cooling process, your temperature will be consistently monitored for hypothermia.
Medications, such as muscle relaxers, may be given to stop shivering. Uncontrollable shivering may increase body temperature and should be avoided. Medications may also be used to prevent seizures.
If needed, you may receive IV fluids to treat dehydration.
Once you’ve been stabilized, a doctor or healthcare professional may recommend tests to determine if your muscles or internal organs were damaged. Tests include:
- imaging tests such as X-rays
- blood tests to measure blood gas, sodium, and potassium levels
- urine test to assess kidney function
- muscle function tests
Thermal instability, or trouble regulating body temperature, is common after heatstroke. You may be kept in the hospital under observation for a day or two, even if no complications occurred.
Your age, overall health, and underlying conditions will all impact the recovery process. So will complications you may have experienced from heatstroke.
You can expect your body temperature to fluctuate more than usual for several weeks. Resting and avoiding physical exertion will help with recovery during this time, as will preventive measures that lower the risk of another occurrence.
A healthcare professional will recommend monitoring tests that assess kidney and liver function during and after recovery. Discuss any unusual symptoms with a doctor such as lowered urine output, confused thinking, or trouble breathing.
Following these tips may help lower your risk of heatstroke and other heat-related illnesses:
- Stay hydrated by drinking plenty of water or sports drinks that contain electrolytes.
- Lower the amount of time you spend outdoors during very hot weather.
- When you’re outside in hot weather, wear lightweight, light-colored clothing that’s loose fitting.
- Install air conditioners or use fans when indoors in hot weather.
- Avoid exercising and other types of strenuous or extreme physical activity outdoors when it’s hot and humid.
You should also avoid leaving a child, animal, or adult in an enclosed hot space such as a car or windowless room that isn’t air-conditioned.
What’s the difference between heatstroke and heat exhaustion?
The main difference between the two is core body temperature. With heat exhaustion, a person has a core body temperature around 100°F (38°C). With heatstroke, a person’s core body temperature reaches 104°F (40°C) or higher.
Heat exhaustion isn’t a medical emergency but heatstroke is.
Can you die from heatstroke?
Yes. When left untreated, heatstroke may lead to organ failure, brain damage, and, in severe cases, death.
How long does heatstroke last?
If you have heatstroke, the faster you’re treated, the easier and quicker your recovery will be. However, you may continue to experience sensitivity to heat for about a week after your symptoms have dissipated.
Heatstroke is a life threatening emergency that requires immediate medical treatment. People with this condition have core body temperatures that reach 104°F (40°C) or higher.
Heatstroke is usually caused by being outdoors in extremely hot and humid weather. It can also be caused by overheated indoor spaces. Babies, children, older adults, and people with certain chronic conditions are at increased risk of heatstroke.
You can avoid heatstroke by keeping yourself cool and hydrated.