The teapot above was photographed in the IR and visible. Note the water level indicated by the higher temperature. Below the same image has had a false colour scheme applied with the temperature scale indicated at right.
The person walking out of the image at top has warmed the floor of the lab slightly and this is visible on the IR camera.
A house with single glaze windows in the visible and infrared. In the false colours scheme yellow is warm. Heat is leaking from the three sets of sliding glass doors.
The image below was taken with a different infrared camera from Indigo Systems Corporation. It shows hot microchips on an operating circuit board. White is hottest, then red, then green, then blue.