When you have a fever, it’s common to have some pretty bizarre dreams. The dreams may seem to repeat themselves on a loop and be scary and surreal at times. Dreams like these are usually referred to as “fever dreams,” and they are common when your body’s thermostat goes up a few notches.1
Schredl M, Erlacher D. Fever Dreams: An Online Study. Front Psychol. 2020;11:53. doi:10.3389/fpsyg.2020.00053
There’s a certain mystery that surrounds these fever dreams. If you’ve ever had a fever dream, you’ve probably wondered: What exactly causes these peculiar dreams? Does everyone have such wild dreams? What is the science behind them? What do they mean psychologically, and can they be interpreted the way we might interpret dreams we have when we’re not running 100+ temperature?
Here, we’ll take a detailed look at fever dreams, including characteristics, causes, meanings, along with some real-life examples and expert commentary.
Characteristics of Fever Dreams
A fever is when your body temperature is elevated, typically in response to illness. Usually, any temperature above 99° F in the morning, or above 100.4° F later in the day, is considered a fever.2 Fevers can make you feel downright awful, and they are also known to affect your cognition and mood. Research has also found that fevers can have strong impacts on sleep. In particular, fevers impact the types of dreams that people have.1
“Typically, fever dreams are more vivid, intense, or disturbing than usual,” says Chelsie Rohrscheib, Ph.D., a neuroscientist and head sleep expert at Wesper. “Fever dreams may also be highly emotional, often negative, sad, or frightening, as changes in neurochemistry during a fever dream may impact the emotional centers of the brain and activate the fight or flight response.”
Fever dreams also tend to be highly repetitive, she says.
Research On Fever Dream Characteristics
Research is limited in terms of specific fever dream characteristics, but the research we have is definitely interesting, and shows that fever dreams are very real and fairly common. Here’s what the research says:
- A 2020 study looked at the results of an online study featuring 164 participants. Of these, 100 shared the details of their fever dreams. Certain themes came up in these dreams. They were generally stranger than normal dreams, had negative tones to them, and also centered around health and temperature, as compared to non-fever dreams.1
- A 2016 study looking at 62 participants’ fever dreams found very similar findings. The study noted that fever dreams were generally more surreal, more intense, and usually had a negative tone.3
- Other research has found similar themes to these studies, as well as other dream attributes, such as increased spatial distortions (moving walls, creatures with outsized legs and arms) and threatening images (menacing dogs and insects, large spheres, and terrorists).1
Causes of Fever Dreams
Having a fever can affect your body in many ways. It’s common to feel cold and hot, or to alternate between the two. You might have a headache, feel nauseous, feel achy, and also experience respiratory symptoms and mood changes. A 2013 study found that having hallucinations and/or vivid dreams is another common symptom of fever.4 Research has also found that even small temperature changes can affect both mood and cognition.1
It makes sense that as our body temperature changes, we would feel symptoms like hotness, and generally feeling icky. But how fevers affect our brain, moods, and dreams is a different story. Let’s take a look at what causes fever dreams.
The Science Behind Fever Dreams
One simple explanation for how elevated body temperature causes fever dreams is the idea that when the body becomes overheated, the brain does as well. As a result, the brain isn’t functioning optimally, which can cause our dreams to be a little weirder than usual.1
“Interestingly enough, this same phenomenon exists when someone is having an allergic reaction, which often causes the body temperature to rise and perspiration to occur,” explains Carder Stout, PhD, a psychologist and expert on the topics of anxiety, depression, trauma, addictions, grief, sleep disorders, and understanding dreams.
“So, it seems that fever dreams occur when the body temperature is elevated and some sort of irritant—allergy, infection, or virus is present,” he says.
Dr. Rohrscheib explains that increased body temps make it more challenging for the brain to regulate sleep, including its ability to control the four stages of sleep. “A fever may result in the early initiation of Rapid Eye Movement (REM) sleep, the stage where we experience dreaming, or too much time in REM sleep,” she says.5
In addition, elevated temperatures may alter the neurochemistry of the brain, “causing dreams that are more intense, weird, or disturbing than usual,” Dr. Rohrscheib says. She notes that neurotropic medication (i.e., medications that directly affect the brain) have a similar impact.
“People who are prone to certain psychological conditions such as depression or certain sleep disorders, may be more sensitive to having fever dreams,” she adds.1
Psychological Interpretations of Fever Dreams
When it comes to fever dreams, what’s happening in our body and brain has a definite effect on our mood and psychology. In fever dreams, “the brain feels the presence of the discomfort in the body and sends a signal to the psyche,” Dr. Stout explains.
Dreams originate in the unconscious part of the psyche but may be triggered by elements in the real world that we are dealing with such as an illness.
Psychologists have been in the business of interpreting dreams since the invention of modern psychology, with both Freud and Jung having theories about what dreams mean in terms of our unconscious thoughts and motivations.6 So what might a fever dream mean, from a psychological perspective?
Fever dreams may have different meanings from one individual to another, says Dr. Stout, but there’s generally a common thread you’ll find among these dreams. Often, the presence of fever in a dream will show up as some type of scary figure or frightening experience, he says.
“So, the illness or fever becomes a character in the dream—a cloaked figure, a monster, snakes or bugs, illegal drugs or illicit substances, you name it,” Dr. Stout describes. “If it is scary and potentially aiming to do harm, then it is the symbol that represents the fever.”
Another way of looking at fever dreams is that they may represent a person try to avoid something or run away from something dangerous, such as a virus or feeling of sickness, says Dr. Stout. The dreams may represent the strong emotions of fear or concerns you have when you are feverish. It’s also why fever dreams may involve negative imagery or scary narratives.
Real-Life Experiences of Fever Dreams
Everyone experiences fever dreams a bit differently, and fever dreams affect folks in different ways, with some people being able to brush them off as just a bizarre dream experience related to their fever, and others finding them more disturbing. It can be helpful to hear what others have experienced in terms of fever dreams, to help you to put your experience into perspective.
In a 2013 study published in the Journal of Pain and Symptom Management, one study participant described their fever dreams as moving “back and forth between a very difficult circumstance and a very comfortable circumstance.” Another described them as “a New York state of mind,” and said the dreams involved “talking to people whose faces I see in the crowd, and they say something and I say something, and it’s usually smart alecky and it’s kind of like that.”4
Dr. Stout shared that his fever dreams are reminiscent of past drug experiences. “I am a recovering addict with 19 years sober,” he said. “When I have a fever dream, I sometimes dream that I am doing cocaine, which elevated my heart rate and made me sweat, much like the fever itself.”
Fever dreams for Dr. Rohrscheib involve a ton of repetition. “When I have a fever, I have dreams that repeat on a loop, in which I have the same dream over and over,” she describes. “I also have dreams where I have a task that is impossible to complete no matter how hard I try.”
Coping With Fever Dreams
Fever dreams aren’t usually anything to worry about. “For the most part, fever dreams are a minor annoyance and go away after a night or two,” says Dr. Rohrscheib. However, fever dreams that occur frequently and aren’t known to be caused by fevers or medications may be taken seriously.
This is because they may be caused by an underlying health condition, like a sleep disorder or mental health condition, Dr. Rohrscheib explains. In this case, you’d want to visit a healthcare professional for advice.
If your fever dreams are disturbing to you emotionally or seem to trigger difficult memories or feelings, it might be time to visit a therapist. “I think it is beneficial to bring dreams into therapy,” Dr. Stout says. “I believe that much wisdom may be gleaned from the action and characters of a dream. Dreams are there to help us and give us clues if we know how to look.”
Finally, although fevers are usually not something to worry about and will generally simply run their course, it’s important to know the warning signs of fevers, and to seek urgent medical care if you experience any of these. Fever warning signs include:2
- Noticeable change in cognitive abilities, like confusion
- Stiff neck and/or serious headache
- Small, flat, purple/red spots on the skin
- Racing heartbeat
- Trouble breathing
- Low blood pressure
- A body temperature over 104° F
The Bottom Line
Fever dreams can be surreal, bizarre, and disorienting. They are likely caused by the elevated temperature and how it affects your brain, your psyche, and your sleep cycles.1 Thankfully, fever dreams aren’t inherently dangerous. However, if you are also experiencing confusion and disorientation or are feeling acutely ill, you should promptly check in with a healthcare professional.