Infrared Camera
Visible light is an example of electromagnetic radiation (discussed more in the Transverse Waves display behind you), but it only makes up a small part of the overall electromagnetic spectrum.
In particular, we cannot see infrared radiation, as it has a lower frequency than what our eyes can detect. You may be surprised to learn that our bodies (and most other things) produce a significant amount of infrared radiation. We cannot see it, but our skin feels it as warmth! This camera is not detecting temperature directly, but this "invisible light."
It converts it into a visible color, indicating where the infrared radiation is coming from. More comes from orange spots, less from purple spots.