Healthy human brains are hotter than previously thought, and can regularly exceed 40°C, according to new study. The study also found that brain temperature drops at night before you go to sleep and rises during the day, reported The Metro.
In healthy men and women, the average brain temperature is 38.5°C. However, deeper brain regions can often be hotter than 40°C, particularly in women during the daytime.
While these temperatures would be considered a fever elsewhere in the body, researchers say they could be a sign of healthy brain function.
“Our work also opens a door for future research into whether disruption of daily brain temperature rhythms can be used as an early biomarker for several chronic brain disorders, including dementia,” said Dr. Nina Rzechorzek, who led the study.
Previously, human brain temperature studies have relied upon data from brain-injured patients in intensive care, where direct brain monitoring is often needed.
“Such high temperatures have been measured in people with brain injuries in the past, but had been assumed to result from the injury,” said Dr John O’Neill, group leader on the study.
But more recently, a brain scanning technique, called magnetic resonance spectroscopy (MRS), has enabled researchers to measure brain temperature non-invasively in healthy people.
The new study by researchers in Cambridge has produced the first 4D map of healthy human brain temperature. These findings could be used to improve understanding, prognosis, and treatment of brain injury.
Researchers studied 40 volunteers, aged 20-40 years, scanning them in the morning, afternoon, and late evening over one day, at the Royal Infirmary of Edinburgh.
Deeper brain structures were frequently warmer than 40°C, with the highest observed brain temperature being 40.9°C.
The study found that female brains were around 0.40°C warmer than that of males, most likely due to their menstrual cycle. Brain temperature also increased with age as the brain’s capacity to cool down deteriorated as people got older.
