A cup of hot green tea! Imaged at 10 microns using a thermal camera.
In this picture, the hottest areas show up as the lightest. The tea’s near boiling, so it’s much brighter than everything else in the photo - the room in the background fades into the dark background. The tea’s in your standard paper cup with a thin cardboard sleeve, and the level of the tea is just slightly above the level of the cardboard sleeve - that’s why there’s such a bright ring around the top of the cardboard sleeve. So, this is thermal evidence that the cardboard sleeve really does do a pretty good job of insulating your hand against hot liquids.
But the best part is definitely the surface of the tea inside the cup. It’s green tea, so it’s transparent when you look at it with a normal camera, but in thermal imaging, it lights up bright and opaque and you can see the interplay of currents of hotter and colder liquid.