Researchers Learn it's Likely All Fungi Sweat

We have no idea why, but it might be in our best interest to find out

Hiya!

Of all our emotions, curiosity might be my favorite. Our dominant emotions — love, hate, anger, sadness, joy — have obvious and specific reasons for evolving. Meanwhile, curiosity is an underappreciated outlier. Sure, it likely evolved to help us learn about the world to survive it, but it also became one of our most complex emotions. Curiosity can be both silly and dangerous. It can cast a spell over us and become all-consuming while we seek answers to our questions.

A curiosity will beckon and call to us until we answer and allow it to lead us on a magical journey. Sometimes, these curious adventures guide us to new understandings, peeling away our naivety to reveal a new layer of Truth. Often, these journies end with new curiosities and adventures down new rabbit holes to explore. Such is the case for today’s topic, in which two microbiologists embarked on a curious adventure of their own and discovered that, like us, fungi sweat.

Following a Curiosity

Radamés Cordero, a microbiologist at Johns Hopkins and lead author of the study I’ll tell you about in a moment, was hanging out in some woods and using an infrared camera to photograph mushrooms. Infrared cameras capture the relative temperatures of objects in an image — warmer objects appear in warmer colors like red, orange, and yellow, while cooler temps appear in blue and purple hues.

When reviewing the pictures, Cordero noticed something curious — the mushrooms appeared colder than their surroundings.

Technically, Cordero wasn’t the first to discover that mushrooms are generally cooler than their surroundings. Still, his curiosity was sparked, and he wanted to know more. So, Codero talked to his colleague Arturo Casadevall, also a microbiologist at Johns Hopkins University and one of the study’s authors, who was likewise intrigued. He said he’d never heard of the phenomenon before. So, the duo teamed up to see whether all fungi possessed this cooling effect.

The Study

Another of Codero and Casadevall’s colleagues at Johns Hopkins, Ellie Rose Mattoon, along with Zulymar Ramos of the University of Puerto Rico, joined the duo for the study, which was published in the National Academy of Science (PNAS) in May 2023.

The researchers photographed wild mushrooms, along with various fungi they grew in a lab, and discovered that the fungi were colder than their surroundings regardless of environment. Even their lab-grown Cryomyces antarcticus culture, which grows in Antarctica, was colder.

Upon closer inspection, the team found the fungi appeared to cool down by sweating — scientifically known as the evapotranspiration of water from their surface.

Casadevall told Live Science to think of when you get out of the shower and you’re covered in water. He says, “You feel cold because some of the water on your skin is evaporating, taking the heat with it.” He also said the fact that fungi do this is “a very interesting … unexplained phenomenon.”

An Experiment