On hot summer days, this thistle is somehow cool to the touch

In the mountains of southern Spain, one type of thistle plant seems to have built-in air conditioning.

The flowers of the thistle Carlina corymbosa are, on average, about 3 degrees Celsius cooler than the surrounding air, ecologist Carlos Herrera reports February 13 in Ecology. The most extreme cooling — sometimes up to 10 degrees C — occurs during the hottest part of the day. This means when the air temperature reaches a sweltering 45° C, the plant’s flowers can remain close to a relatively cool 35° C.