Buzz
When you're sick, getting a restful night’s sleep can feel almost impossible for various reasons. Whether it's the struggle to fall asleep or stay asleep due to a stuffy nose, persistent cough, or a mix of those uncomfortable symptoms, rest can seem out of reach.
Fevers can make it even harder to get quality sleep, especially due to fever dreams—strikingly vivid, bizarre, or unsettling dreams that happen when you’re running a fever. According to the Sleep Foundation, fever dreams can involve “spatial distortion,” such as walls shifting or objects melting, “threats or danger,” ranging from creepy insects to terrorists, and illness itself. If you were to dream like this when you're not sick, you’d probably consider it a typical nightmare. But because these odd dreams occur more often during fevers, people believe there must be a connection between the two.
This isn’t a new idea. English speakers have been discussing fever dreams since at least the early 1800s. The first recorded mention comes from a letter written by Samuel Taylor Coleridge in 1801. “Even the Forms which struck terror into me in my fever-dreams were still forms of Beauty,” he wrote. As per the Oxford English Dictionary, the term “fever dream” likely originates from an even older German word: Fiebertraum, which also means fever dream.
While much about fever dreams remains unclear, there’s some evidence suggesting that they differ from regular dreams for certain individuals. A 2016 retrospective study asked 62 participants to recount their past fever dreams, revealing that these dreams were 'more bizarre, more emotionally intense, and often negatively toned' compared to the regular dreams of an age- and gender-matched sample. In a 2020 survey with 164 participants (co-conducted by dream researcher Michael Schredl, who also co-authored the 2016 study), 100 people reported having fever dreams. Researchers found that these dreams 'featured more references to health and temperature perception than their ‘normal’ recent dreams.'
As to why fevers lead to strange nightmares, scientists have some theories. One hypothesis is that the brain processes sensations abnormally when we have a fever. Dr. Beth Malow, director of Vanderbilt University Medical Center’s sleep division, explained in 2020 to Health: '[One] theory is that the brain doesn’t process sensations normally when we have a fever.' So, the intense heat of your fever could translate into dreams of melting objects and unexpected dangers.
The vividness of fever dreams might be tied to how fever disrupts REM sleep—the deepest stage of sleep where most dreams occur. According to Dr. Alcibiades Rodriguez, medical director of NYU Langone Health’s Comprehensive Epilepsy Center-Sleep Center, in an interview with Health: 'If we get a spike in fever during REM sleep, we may feel more uncomfortable and experience micro-arousals (shifts between deep and light sleep). This increases the likelihood of us remembering our dreams.'
In summary, from a scientific perspective, fever dreams remain a somewhat mysterious phenomenon. However, the figurative meaning of the term 'fever dream' is somewhat clearer. It can refer to anything—be it a plan, a story, a piece of art, a TV show, an acid trip, etc.—that feels disorienting, detached from reality, or just strikingly evocative. And considering that actual fever dreams are usually unpleasant, calling your friend's new short film a 'fever dream' might not carry the compliment you intended to give.
