Hyperpyrexia

Hyperpyrexia is a high body temperature above 106.7 degrees Fahrenheit (41.5 degrees Celsius). This change to your body temperature happens because your brain tells it to go up.

Hyperpyrexia is an emergency and requires immediate medical attention.

The expected temperature of an adult human is 98.6 F (37 C). The temperature for a healthy person can range from 97.8 F to 99.1 F (36.55 C to 37.27). This range is the desired temperature on your body’s thermostat. It’s known as the “hypothalamic set point.” If you have hyperpyrexia, part of your brain changes the thermostat’s set point to increase your body temperature.

How does the hypothalamus affect hyperpyrexia?

The hypothalamus is an organ in your brain that regulates your temperature. If you have hyperpyrexia, your hypothalamus increases your body temperature above what’s expected.

A healthcare provider may refer to hyperpyrexia as a “hypothalamic fever.” This is because the part of your brain that manages your temperature isn’t working correctly.

What is the difference: hyperpyrexia vs. a fever vs. hyperthermia?

Hyperpyrexia is a body temperature above 106.7 F (41.5 C). It happens when your brain tells your hypothalamic set point to increase.

A fever is a body temperature above 100.4 F (38 C). Your hypothalamus increases your body temperature during a fever to fight off an illness or an infection.

Hyperthermia is a body temperature higher than expected (99 or 100 F / 37.2 or 37.7 C). It happens when your body absorbs more heat than it can release. It doesn’t affect the temperature set point.

Also, hypothermia is the opposite of hyperthermia, when your body temperature drops below 95 F (35 C).

Hyperpyrexia symptoms

The main symptom of hyperpyrexia is a body temperature higher than 106.7 degrees F (41.5 C). If you have a high body temperature, visit the emergency room or contact 911 (or your local emergency services number). This condition is life-threatening without quick treatment.

A high body temperature can make you feel:

• Dizzy or lightheaded
• Flushed or pale
• Nauseated
• Sweaty
• Thirsty
• Tired
• Weak

If your temperature stays high, you may have severe symptoms like:

• Confusion
• Dehydration
• Fast heart rate
• Loss of consciousness
• Seizures
• Stiff muscles or muscle cramps

Hyperpyrexia causes

An increase in your body’s expected temperature (hypothalamic set point) causes hyperpyrexia. The temperature increase can happen due to:

• A brain hemorrhage
• A negative reaction to anesthesia or medication (SSRIs or antipsychotic medications)
• A tumor
• Addictive substances
• An overactive thyroid (thyroid storm)
• Brain trauma
• Severe bacterial or viral infections (like sepsis or COVID-19)

Complications of hyperpyrexia

The condition can be deadly if it isn’t treated quickly. Hyperpyrexia can make it hard for your organs and body systems to work, including your:

• Brain
• Heart
• Lungs
• Gastrointestinal system
• Liver
• Kidneys

As a result, it can lead to:

• Pressure or swelling on your brain (intracranial pressure)
• Permanent brain damage
• Coma

How doctors diagnose hyperpyrexia

As hyperpyrexia is an emergency, you’ll likely be diagnosed in the ER. A healthcare provider will check your temperature. They may check more than once and in different places on your body to make sure it’s correct. They’ll also ask about your symptoms and health history.

Testing, like blood and imaging tests, may help find the cause.

How is hyperpyrexia treated?

Treatment focuses on cooling down your body and treating the cause. To lower your body temperature, your care team may use the following:

• Ice packs
• A cool, damp cloth
• A cool bath

Depending on the cause, additional treatment may include:

• Taking fever reducers (antipyretics) like ibuprofen, acetaminophen or NSAIDs (if age appropriate)
• Taking antibiotics or antivirals for an infection
• Stopping anesthesia
• Taking corticosteroids for a hemorrhage
• Receiving fluids through an IV to prevent dehydration
• Undergoing surgery to remove a tumor or severely damaged tissue from an infection or to treat the underlying cause

When should I go to the ER?

Visit the emergency room or contact 911 or your local emergency services number if you have a higher-than-normal body temperature. A body temperature above 99 or 100 degrees Fahrenheit is too warm (37.2 or 37.7 degrees Celsius). A temperature above 106.7 F (41.5 C) needs immediate medical attention.

What questions should I ask my doctor?

• What caused a high body temperature?
• What are the side effects of treatment?
• Did hyperpyrexia cause any damage to my body?
• How do I prevent hyperpyrexia from happening again?

What’s the outlook for hyperpyrexia?

Hyperpyrexia is a medical emergency. If you have a temperature above 106.7 F (41.5 C), get help right away. It can cause permanent organ damage or be life-threatening if your body temperature doesn’t lower.

Quick treatment can lead to a positive outlook. Your provider will tell you what to expect and how to take care of yourself.

Can hyperpyrexia be prevented?

You can’t prevent all causes. But you can reduce your risk by:

• Letting your provider know if you have had a negative reaction to a medication or anesthesia before
• Protecting yourself from injury or avoiding activities that could lead to an injury
• Treating or managing any underlying health conditions
• Avoiding any addictive substances