Fever dreams are difficult to study. (You can’t easily visit a sleep lab when you have the flu, after all.) But in 2020, dream researchers Michael Schredl of Heidelberg University in Germany and Daniel Erlacher of the University of Bern in Switzerland surveyed 164 people. They found that fever dreams live up to their reputation for being beyond weird, but they and included more negative and fewer positive emotions than other dreams.
“Normal” dreams often feature interactions with people, while in fever dreams, people appear less often. Unsurprisingly, fever dreams are also more likely to feature health-related topics and a keen awareness of temperature.
Being chased by a giant ball of lava may seem a little extreme but other research has shown that dreams often incorporate bits and pieces of the waking experience. They call this the continuity hypothesis. So, if you’re burning with fever, dreaming of a lava ball is keeping with the concerns of your waking life.
Schredl and Erlacher also raise the possibility that the cognitive impairment brought on by fever might contribute to the strangeness of dreams. “The basic idea is that the ‘over-heated’ brain is not functioning properly and therefore dreams are more bizarre,” they write, pointing to previous research by Schredl showing that the severity of psychotic symptoms in schizophrenic patients during the day is relative to the degree of weirdness of their dreams at night.
