Fever Dreams

By McKenzie Hyde
Last Updated On June 18th, 2020

Our dreams intrigue us, especially the bizarre — dreams with no connection to real life. Dreams are said to be inspired by our memories, interests, events, and day-to-day activities. Dreaming…

Fact checked by
 Michele Roberge Michele Roberge

Michele Roberge

Michele Roberge is a Registered Polysomnographic Technologist and a Registered Radiologic Technologist. Michele currently leads a 4-bed, hospital-based sleep disorder center in Florida, which is also home to one of the largest sleep apnea support groups in the nation.

Fever Dreams

Our dreams intrigue us, especially the bizarre — dreams with no connection to real life. Dreams are said to be inspired by our memories, interests, events, and day-to-day activities.

Dreaming of strange scenarios with negative connotations disturb us —such dreams occur during illnesses, better known as “fever dreams.” Though termed “fever dream,” these are akin to nightmares that we experience during fever.

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Fever is our body’s way of fighting an infection. When we have a fever, our body temperature goes up, usually above 101 degrees, triggering our chances of experiencing a fever dream.

What Is a Fever Dream?

The normal temperature of a human body usually ranges between 97 and 99 degrees. But when our body is fighting a virus, bacteria, or an infection our immune system goes into action. The core body temperature shoots up between two to seven degrees, triggering our body’s natural defense mechanism.

All kinds of bacteria, viruses, and infections are temperature-sensitive pathogens —higher temperatures prevent pathogens from multiplying in our bodies. Though having a fever is an uncomfortable experience, it is actually our body’s way of attacking harmful pathogens.

In a fever, we see symptoms like high body temperature, aches, chills, sweating, and sometimes bizarre dreams. These vivid dreams, often disturbing in nature, leave a lasting impression.

Why Do We Experience Fever Dreams?

Adults typically experience four to six sleep cycles through the night, alternating between Non-Rapid Eye Movement (NREM) and Rapid Eye Movement (REM). NREM is the more peaceful phase of sleep and takes up about 75 percent of sleep time, while the remaining 25 percent is spent in REM sleep.

Dreams may occur during any stage of sleep, but we are more likely to remember the ones that we experience during REM. During this stage of sleep, our eyes move rapidly behind closed lids while having vivid dreams. Our brain is also responsible for the natural thermoregulation of our body heat, particularly the hypothalamus, but during REM, temperature regulation is not as efficient as during the day.

When we have a fever, our body is fighting an illness. During fever, the hypothalamus triggers an increase in body temperature to fight illness-causing pathogens. Elevated temperature is known to cause sleep disturbances like insomnia, or fever dreams.

According to research, the bizarre and intense nature of fever dreams is related to high body temperature. Fever has an effect on the cognitive processing of our brain during sleep. Since our brain is unable to perform normally during a high fever, it tends to produce dreams which are unpleasant and unusual in nature. In a study, roughly 94 percent experienced fever dreams describing them as negative.

Fever Dreams

“Fever dreams can be explained by the fact that the same part of the brain is responsible for promoting sleep and regulating body temperature,” says Michele Roberge, RT(R), RPSGT, a neurodiagnostics lead technologist at Parrish Sleep Disorder Center. “When the hypothalamus works to increase body temperature to combat an infection, this can cause disruptions in sleep – leading to what we refer to as ‘fever dreams’. The vivid fever dreams most likely occur during our REM cycle when our brain waves are most active. Although there are several theories about dreams, they remain a scientific mystery.”

What Do We See in Fever Dreams?

Fever dreams are nightmares we experience as a result of having a high body temperature. These are emotionally intense and ghastly dreams with disturbing negative connotations. Since high body temperature makes it difficult to sleep, the disturbing nature of fever dreams increases sleep disruptions. Some of the common themes and visuals in fever dreams have been described as:

  • Associated with heat and fire, with visuals like the sky on fire or wax statues melting down. This could be because the body temperature is high and the brain triggers this heat, to keep pathogens at bay. The brain’s awareness of this high body temperature could be a probable reason behind fever dreams being associated with heat.
  • Repetitive actions or events.
  • Experiencing a fever dream can sometimes be like watching a sci-fi film replete with images typical of the genre like spatial distortions, blackness, and creatures with oversized limbs moving around.
  • Strange dreams with a high recall value of every minute detail.
  • Often associated with something that is intimidating, and stress-inducing.
  • Sometimes fever dreams end with a feeling of claustrophobia or vertigo.

Fever Dreams Like Lucid Dreams

Fever dreams have some similarities with lucid dreams because they both have a high recall value. They usually occur during the REM stage of sleep, when the brain is more active. The difference is lucid dreams are not linked to fever. They are sometimes controllable and don’t always have a negative meaning to them. But fever dreams are almost always emotionally intense nightmares experienced during an illness.

You can train yourself to lucid dream, as lucid dreaming sometimes has some advantages, such as boosting creativity or dispelling phobias. Sometimes lucid dreams are used professionally as part of therapy. But fever dreams don’t have any such advantage. Fever dreams are closer to nightmares or emotionally intense dreams with negative undertones due to fever.


Does heat cause weird dreams?

Yes. The brain regulates our body’s temperature, and when we have a fever our body’s temperature increases to fight pathogens. Due to excess heat from the high body temperature our brain is unable to perform normally during a fever, it produces unpleasant and unusual dreams.

Do you dream more when you are sick?

If you are down with a fever, sleeping becomes difficult due to high temperature and body aches. Disturbed sleep leads to emotionally intense dreams with a negative tinge to it.


You don’t have control over fever dreams, and there is nothing that you can possibly do to prevent it. High body temperature affects the brain’s normal performance and sometimes produces unusual dreams. Treat them as a temporary symptom of a fever, which your body experiences to fight illnesses. Once your body temperature goes back to normal, your fever dreams will fade away too.

This article is for informational purposes and should not replace advice from your doctor or other medical professional.

About the author

McKenzie Hyde is a Certified Sleep Science Coach and a full-time writer focused on sleep health and the mattress industry. She currently writes articles on a variety of topics, ranging from sleep hygiene to the newest trends in the mattress and bedding industry. Just some of the topics she has covered include best sleep practices for students, the consequences of going without sleep, and choosing the right bed if you suffer from back pain. McKenzie Hyde holds a Master of Arts degree from Utah State University where she studied literature and writing. While there, she taught argumentative writing and wrote a variety of articles and analyses for literary and academic journals.

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