Almost any picture you see of a koala, they are hugging a tree. It’s their classic pose. But did you know there was a reason for it? Well, researchers at the University of Melbourne in Australia have discovered why they do it. According to the scientists, they hug the tree to cool down their bodies.

The researchers observed the koalas with thermal cameras throughout the year. They noticed that on really hot summer days the koalas moved down to the lower parts of the trees where it was cooler and they tended to hug the trees closer.

Measurements taken with the thermal cameras showed a dramatic difference between the koalas’ body temperature and the outside temperature. In fact, they were as much as 6 degrees cooler on days when the temperature was over 39 degrees Celsius.

Koalas tend to have thinner fur on their abdomens. The researchers suspect that this thinner fur helps them make closer contact with the tree, which in turn facilitates cooling.