RADAMES JB CORDERO FROM "R. J. B. CORDERO, E. R. MATTOON, Z. RAMOS, A. CASADEVALL, THE HYPOTHERMIC NATURE OF FUNGI. PROC NATL ACAD SCI USA 120, E2221996120 (2023)."

SWEATY SPECIMEN: Scientists have found that all fungi, like this fly agaric, are able to regulate their own temperature through evaporation.

Microbiologist Radames Cordero was testing a heat-sensing thermal camera in the woods when he noticed that the mushrooms around him appeared “intensely blue.” This meant they had a low surface temperature. His team at Johns Hopkins University in Maryland decided to measure the heat of other fungi, including mushrooms, molds, and single-celled yeasts. All were several degrees cooler than their surroundings.

The scientists discovered that all fungi release water to keep cool—just like people do when we sweat! As water molecules evaporate, or change from a liquid to a gas, they carry heat away from the fungi’s surface.

For fun, the scientists created a mushroom-powered air conditioner—a box of mushrooms with a fan blowing over them. Within 25 minutes, the fungi’s cooling power caused the surrounding temperature to drop 10°C (18°F)!