Designer Hideyuki Kumagai must have been inspired by the seasonal colors of nature when he designed this thermometer.
Stick the leaves to your window, or make a bush at your office garden, and they will tell you how hot it is by changing color. If it is nice and warm (20-25 degrees) the leaves stay fresh green. When it becomes cooler they slowly turn brown. And if they turn yellow, then you know it is time to cool down.