What is a Fever Dream?

While we dream every night, when we’re sick, our dreams can be particularly vivid or frightening. The intense dreams we experience during an episode of high body temperature are called fever dreams.

Sometimes these dreams are just abnormally dramatic and memorable, but for some people, they can be really upsetting.

So what exactly is a fever dream? When do we get them? Why do we have them? Below, we’ll answer these questions and give you some info on what to do if you’re experiencing disturbing dreams every time you catch the sniffles.

When We Get Fever Dreams

Of course, the most obvious time we get fever dreams is when we have a fever—a core body temperature over 100.4 degrees Fahrenheit. Our normal body temperature is between 97 and 99 degrees.

Symptoms of fever may include:

• Chills or shivering
• Sweating or clammy skin
• Headache
• Muscle aches or weakness
• Fatigue or lethargy
• Loss of appetite
• Warm or flushed skin
• Rapid heart rate
• Respiratory symptoms like cough or shortness of breath
• Fever dreams or vivid hallucinations

When we’re fighting infection, one of our immune system’s main defense mechanisms is turning up the heat. Most viruses and bacteria thrive when our body is at its normal temperature, so upping the temperature by a few degrees makes it a lot harder for temperature-sensitive pathogens to survive.

This means you’re most likely to have fever dreams when you have an infection or some other illness that causes your body to experience higher temperatures than normal.

However, there are other scenarios where you can still experience fever dreams. For instance, if your core temperature is raised because of conditions outside of your body (like heavy wearing layers when it’s warm outside or spending too much time in the sun)—an issue called hyperthermia—you can experience hallucinations and fever dreams. In fact, these can be symptoms of both heat exhaustion and heatstroke.

What Differentiates Fever dreams from other dreams?

• Emotional Intensity: Fever dreams are often more emotionally charged, with heightened feelings of fear, confusion, or distress compared to the typical range of emotions in regular dreams.
• Vivid and Bizarre Content: They tend to have unusual, surreal, or illogical narratives, often involving themes like heat, danger, or fantastical scenarios.
• Disruptive Nature: Unlike normal dreams, fever dreams frequently wake the sleeper, interrupting restful sleep and leaving a lasting impression.
• Triggered by High Temperature: Fever dreams are closely linked to elevated body temperature, whereas ordinary dreams are part of the brain’s normal sleep cycle.
• Higher Recall: People are more likely to remember fever dreams due to their intensity and the sleep disturbances they cause.

These distinctions make fever dreams a unique, albeit sometimes unsettling, part of the body’s response to illness.

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Fever Dreams and Their Meanings

Meaning behind a fever dream is not objective. The meaning of fever dreams is largely subjective and not fully understood. Unlike ordinary dreams, which are sometimes linked to subconscious thoughts or emotions, fever dreams are primarily influenced by the brain’s response to elevated body temperature.

Fever dreams and nightmares may seem similar because both are intense and can be emotionally distressing, but they have distinct differences. 

Fever dreams are triggered by elevated body temperature during illness and often include bizarre, surreal, or fragmented scenarios influenced by the fever’s effects on brain activity. 

In contrast, nightmares are typically connected to emotional stress, anxiety, or unresolved fears and occur as part of the normal sleep cycle, without the need for physical illness. 

Fever dreams also tend to involve themes like heat or discomfort, whereas nightmares often center around fear or danger.

Fever dreams and lucid dreams are at opposite ends of the dreaming spectrum. 

Fever dreams are intense, uncontrolled, and often unsettling, caused by physiological disruptions like fever. 

In contrast, lucid dreams occur when the dreamer is aware they are dreaming and may even have control over the dream’s narrative. 

While fever dreams are typically chaotic and influenced by illness, lucid dreams are characterized by clarity and intentionality, often providing an opportunity for creative or enjoyable experiences.

Why We Get Fever Dreams

Fever dreams occur when the body experiences a rise in temperature due to illness, typically in response to infections such as the flu, a cold, or other conditions that cause fever. The phenomenon of fever dreams can be attributed to several factors related to the way a fever affects the brain and sleep cycle. 

Since nobody knows for sure why we experience regular dreams in the first place, the same holds true for why we experience fever dreams. Scientists believe high core body temperatures disrupt the brain’s ability to think normally, leading to lower cognitive function and sometimes even wake time hallucinations.

The hypothalamus, a region of the brain that regulates body temperature, is also involved in controlling sleep and emotions. 

When fever alters the function of the hypothalamus, it can affect the sleep-wake cycle, making dreams more intense or fragmented. The changes in brain function caused by fever can lead to irregular REM sleep patterns, contributing to the vividness and oddness of fever dreams.

Combine the feverish brain’s cognitive impairment with the fact the core body temperature rises during Rapid Eye Movement sleep (REM sleep), and this increased elevation may impact your brain’s normal dreaming activity, leading to intense or unpleasant dreams.

However, when you have a fever, the body’s temperature regulation is disrupted, which causes fragmented or lighter sleep. 

This disruption means that you’re more likely to wake up during the night, and when you do return to sleep, you might enter REM sleep more quickly. As a result, you experience intense dreams that can feel disjointed or out of the ordinary.

Individuals with psychological conditions like depression or certain sleep disorders may be more susceptible to experiencing fever dreams. Fever dreams are deeply influenced by the connection between the body and brain, which can significantly impact our mood and mental state. 

According to Dr. Stout, the brain registers the physical discomfort caused by illness and translates it into psychological signals that shape our dreams.

What Fever Dreams Are Like

All fever dreams are vivid, but the bad news is the overwhelming majority of people who experienced them identified them as upsetting.

When you’re having a fever dream, you may experience more intense emotions, more bizarre narratives, and/or more harrowing situations than during your normal dreams. These strange dreams can and do interrupt sleep. They also have some common themes.

a. Heat or Fire

A lot of times the content of dreams induced by fever might include things like forest fires, melting objects, or heat waves. This might be due to the brain’s awareness of the body’s elevated temperature.

In addition to visions of fires and melting objects, some fever dreams might feature an overwhelming sensation of heat or burning, possibly reflecting the body’s own elevated temperature and discomfort. The body’s physical response to fever might trigger the brain to create scenarios where the dreamer is overwhelmed by heat or flames.

b. Stressful or Intimidating Situations

Some people reported dreams like recurrent childhood nightmares suddenly returning to them in adulthood. Many also reported feeling endangered during recent fever dreams.

You might experience anxieties about death, accidents, violence, or personal phobias during one of these bizarre dreams. Negative dream emotions like sadness and fear and scary health-related themes are also common.

Another common theme in fever dreams is the recurrence of deeply ingrained anxieties, such as childhood fears or unresolved stressors. These situations often feel heightened, like an impending disaster or confrontation, creating a sense of vulnerability or helplessness. The anxieties may not always align with the fever’s immediate causes but can tap into the dreamer’s subconscious fears, amplifying emotional stress.

c. Fantastical Elements

Fever dreams often involve bizarreness such as alien creatures, distorted sensory perception, and vastly different environments from real life.

These elements can feel completely bizarre, such as interacting with creatures that defy logic, floating, or traveling through impossibly surreal landscapes. The fever’s impact on the brain may cause these fantastical elements to feel unusually vivid and overwhelming.

d. Higher Dream Recall Value

Another big thing about fever dreams is they have a high dream recall frequency, meaning you remember them more often than regular dreams. This could be due to their intensity or unpleasantness, and it could also be because these dreams tend to interrupt REM sleep with more frequency. When your sleep is disturbed during a dream, you’re more likely to remember that dream.

The high emotional intensity, distress, or confusion they evoke also contributes to their memorable nature. Because these dreams disrupt normal sleep cycles, they tend to be more persistent and are remembered in greater detail, often lingering in the mind after the fever has subsided.

SEE ALSO: Maladaptive Daydreaming: Symptoms and Treatments

Fever Dreams Impacts on Sleep

The discomfort caused by fever—such as chills, sweating, or body aches—can also contribute to tossing and turning, further disturbing your rest. The overall effect is often fragmented sleep, which may leave you feeling groggy and less refreshed the following day. In some cases, fever-induced dreams may be accompanied by nightmares, increasing feelings of anxiety or discomfort.

Fever dreams can disrupt sleep in several ways:

1. Disturbed Sleep Cycle: Elevated body temperature from a fever can interrupt your sleep cycle, preventing deep, restorative sleep and causing frequent awakenings.
2. Intense Dreams: Fever can trigger vivid and intense dreams, which can be unsettling and contribute to disrupted sleep.
3. Fragmented Sleep: The discomfort from fever and dreams can lead to waking up more often, making it harder to stay asleep for extended periods.
4. Restlessness: Physical discomfort, sweating, and vivid dreams can cause restlessness, making it difficult to find a comfortable sleeping position.
5. Increased Sweating: Nighttime sweating caused by fever can also wake you up, further disturbing your sleep.

How to Prevent Fever Dreams

For some people, intense dreams while they’re sick don’t really bother them, but for others, fever dreams are often nightmares that can cause anxiety surrounding sleep, fear of falling asleep, or in the severest of cases, psychological trauma.

There’s no magic bullet for all fever dreams, but if you want to prevent them, controlling your core body temperature is a good start.

To keep your fever down:

• Eat foods that are easy on the stomach (like those on the BRAT diet)
• Drink lots of fluids
• Get plenty of rest
• Take an NSAID like ibuprofen or aspirin to lower fever
• Shower in lukewarm or cool water

In addition, here are some additional tips that may help:

• Try not to stress over nightmares; focus on staying cool and resting well.
• Maintain a balanced diet and practice regular hand hygiene.
• Keeping your environment tidy and organized can help calm your mind.
• To avoid nasal and throat irritation, ensure the air is humidified by using a humidifier.

FAQs

Is a fever dream the same as a lucid dream?

Not really. While these dreams are both extremely vivid, lucid dreams happen when you know you’re asleep and dreaming. This consciousness can sometimes allow you to learn to control the content and narrative of your dreams. By contrast, fever dreams are entirely out of your control and you normally aren’t aware they’re dreams while they’re happening.

What makes fever dreams so weird?

Fever dreams are often strange and bizarre due to the impact of fever on the brain. When your body temperature rises, it can interfere with the brain’s normal processes, particularly during sleep. Fever disrupts the sleep cycle, especially the REM (Rapid Eye Movement) stage, which is when most vivid dreaming occurs. This disruption leads to more intense, fragmented, and surreal dreams.

Additionally, a fever can increase brain activity, making the mind more active and more prone to generating vivid or distorted dream imagery. Combined with physical discomfort from the fever—such as sweating, chills, and overall illness—these factors contribute to dreams that feel unusually strange or unsettling.

Is there any illness that causes fever dreams?

Fever dreams can occur with a variety of illnesses that cause fever, including:

• Infections: Viral and bacterial infections, such as the flu, pneumonia, or COVID-19, are common causes of fever and fever-related dreams.
• Cold or Respiratory Infections: Illnesses like the common cold, sinus infections, or bronchitis can lead to fever and disrupt sleep.
• Influenza (Flu): The flu often comes with high fever, which can trigger vivid or unsettling dreams.
• Malaria: This parasitic infection commonly causes high fever and may lead to vivid, strange dreams.
• Infections like meningitis or encephalitis: More serious infections that affect the brain can lead to fever and contribute to intense dreams.
• Other conditions: Autoimmune diseases, severe dehydration, or reactions to certain medications can also cause fever and increase the likelihood of experiencing fever dreams.

Essentially, any illness that raises the body’s temperature significantly can potentially lead to fever dreams.

Is it bad to sleep with a fever?

No. A fever isn’t like a concussion. In fact, if you’re sick, sleep is an important part of getting better. Rest can help boost your immune system and get you well again faster, and it also allows your body to devote more energy to healing itself rather than other things like working, studying, or exercise.

Why are fever dreams so often nightmares?

There’s not really a clear answer to this one. We know the body has a harder time controlling its internal temperature during the REM stage of sleep. We know fever raises the core temperature. And we know body temperature has a profound effect on cognition. But why all this seems to lead almost exclusively to bizarre and unpleasant dreams, rather than fun and enjoyable dreams, is still mostly a mystery that might never be solved by future studies.

Do other species experience fever dreams?

While we know other animals besides humans experience dreams (dogs are a good example), there’s not much research on whether they have more intense dreams during illness. However, since animals do have complex and vivid dreams, and they’re also similar to humans in a number of other ways, it wouldn’t be implausible to think they can experience fever dreams while they’re sick.

How do dreams occur during fever?

Fevers cause dreams because they disrupt the brain’s normal sleep processes, particularly during the REM (Rapid Eye Movement) phase, when most vivid dreaming occurs. When your body temperature rises, it can interfere with the regulation of your sleep cycle, making it harder to reach the deeper, more restorative stages of sleep. This leads to more frequent awakenings and lighter sleep, which increases the likelihood of experiencing vivid or strange dreams.

Additionally, the body’s elevated temperature during a fever can trigger increased brain activity as the body works to fight the infection. This heightened brain activity often results in more intense, emotional, or surreal dreams. The physical discomfort caused by fever, such as chills, sweating, or body aches, can also influence the mind, leading to dreams that feel particularly strange or unsettling.

Are fever dreams ever a sign of something serious?

Since fever dreams can occur for nothing more than a common cold, they’re not a sign of serious illness in and of themselves. However, if you have a persistent fever or illness, there could be something else going on. The general rule is if you have mild symptoms like a low-grade fever or stuffy nose that last more than a week or two, you should see your doctor.

Also, if you have a high fever—over 103—it’s a good idea to call your doctor right away. Remember, any fever over 104 is an emergency because it can cause lasting brain damage.

Bottom Line

Fever dreams can be vivid and often upsetting, but thankfully they’re not normally dangerous on their own, and they tend to go away when your illness does.

While fevers are usually harmless and tend to resolve on their own, it’s important to recognize when urgent medical care is necessary. Warning signs that require immediate attention include:

• Sudden confusion or changes in mental state
• Intense headache and/or neck stiffness
• Small, flat purple or red spots on the skin
• Rapid heartbeat
• Difficulty breathing
• Low blood pressure
• A body temperature higher than 104° F

If you have disturbing fever dreams frequently, the best way to prevent them might just be to avoid getting sick. In fact, “if you’re sick enough to be running a fever, the distress and discomfort of being ill may turn up in your dreams,” says Dr. Alicia Roth, DBSM. Wash your hands frequently, don’t drink or eat after others, and avoid touching your face as much as possible. Your brain and your body will both thank you.