A high fever and conditions that lead to heat stroke are potential causes of seizures. External heat can trigger seizures in people with one specific epilepsy syndrome.

Your body temperature needs to stay within a narrow range for all your organ systems to function properly. A high body temperature can cause:

Seizures are uncontrolled bursts of electrical activity that start suddenly in your brain. According to some research, about 8% of people will have at least one seizure in their lifetime.

You may experience a seizure if you have a high fever or if you develop heat stroke.

Read on to learn more about heat-induced seizures, including why they happen and how you can prevent them.

Heat can potentially cause seizures if you develop heat stroke or have a high fever.

A fever can increase the excitability of the neurons in your brain, and this can lead to seizures, especially if you have a seizure disorder. Animal studies suggest that almost all animals will develop seizures if they’re exposed to heat long enough.

Heatstroke and seizures

Heatstroke can happen when your body temperature rises higher than 104°F (40°C) due to hot weather or strenuous physical activity. Neurological complications of heatstroke include:

In a 2018 case study, researchers presented a 20-year-old man who collapsed after running for 3 hours in 102.2°F (29°C) heat.

On his fourth day in the hospital, he developed a severe headache and had six generalized tonic-clonic seizures lasting 1–2 minutes each. He was able to leave the hospital after 2 weeks.

Fever and seizures

Fever is the most common seizure trigger for children between 5 months and 6 years of age. Fever often occurs due to an infection, but fever alone can also potentially trigger seizures.

Febrile seizures — a type of seizures caused by a high fever in young children — are typically triggered by a body temperature above 101°F (38°C).

Febrile seizures, or seizures related to heat stroke, produce the same symptoms as seizures that aren’t related to fever or heat stroke. Symptoms can include:

About 1 in 25 children experience at least one febrile seizure, with the greatest risk coming at the age of 2 years.

People with Dravet syndrome are particularly prone to heat-related seizures. Dravet syndrome is a severe epileptic syndrome usually caused by mutations in the SCN1A gene. It typically develops early in childhood or infancy.

If you have a well-managed seizure disorder, your doctor can give you guidelines for when you can skip calling for help. The Centers for Disease Control and Prevention (CDC) recommends calling emergency medical services if you or somebody you’re with:

  • has a seizure for the first time
  • experiences trouble breathing or walking after a seizure
  • has a seizure lasting more than 5 minutes
  • has a second seizure shortly after the first
  • has a seizure in water
  • sustains an injury during a seizure
  • has a health condition such as diabetes, heart disease, or pregnancy and experiences a seizure
Medical emergency

Heatstroke is also a medical emergency that requires immediate attention. Call emergency medical services or go to the nearest emergency room if you or somebody you’re with has symptoms of heatstroke, such as:

  • a feeling of being unwell even after 30 minutes of sitting in a cool place
  • a very high body temperature
  • skin redness (which can be harder to see on dark skin) and a lack of sweating
  • a rapid heartbeat
  • shortness of breath
  • confusion
  • seizures
  • loss of consciousness

Doctors can use a variety of tests to diagnose seizures, such as:

Antiseizure medications are the primary treatment for seizures. Most febrile seizures don’t need treatment, but doctors occasionally prescribe medication.

Heatstroke may require emergency medical treatments such as:

  • the use of cold water, ice, or other means to lower your body temperature
  • saline solution given through an IV (directly into your veins)
  • intubation to address trouble breathing
  • medications given through an IV

According to the CDC, you can prevent heat-related illness by:

  • wearing light and loose-fitting clothing when outside in the heat
  • staying cool inside as much as possible and taking cool showers on extremely hot days
  • limiting strenuous activity to the coolest parts of the day on hot days
  • pacing yourself when exerting yourself in the heat and stopping if the heat makes your heart pound or leaves you gasping for breath
  • wearing sunscreen
  • not leaving your children or pets in a car on a hot day
  • drinking plenty of fluids but avoiding very sugary or alcoholic drinks

Here are some frequently asked questions people have about heat-induced seizures.

Can heat cause seizures in adults?

Adults can potentially experience seizures if they have a high fever or develop heatstroke.

Can heat cause seizures in toddlers or babies?

Fever is the most common cause of seizures in children under 6 years old. Febrile seizures are usually triggered by a fever above 101°F (38°C).

Is a heat-induced seizure the same as heatstroke?

A seizure is not the same as heatstroke. Seizures can be associated with heat if a person has a very high fever or if they have heatstroke. Heatstroke is a serious illness that occurs when your body can no longer regulate its temperature.

External heat is especially likely to trigger seizures in people with a rare type of epilepsy called Dravet syndrome. Fever is the most common cause of seizures in young children.

It’s critical to get immediate medical attention if you or somebody you’re with develops symptoms of heatstroke, such as a very high body temperature, loss of consciousness, or confusion.