Thermal Imaging has been around for nearly a quarter of a century, and has grown considerably in the capability of providing scientists with heat radiation images that would normally be invisible to the naked eye. Thermal imaging is simply made up of a thermal scene, a lens, a sensor, and a display. But how do you focus heat? What kind of sensor detects heat, and how do you display it? This article offers a short Infrared 101 overview, and covers fundamental terms and concepts of thermal imaging. Download the full paper for more in depth information.