Interesting:

Iscon’s patented, thermo-conductive technology combines infrared (IR) and heat transfer, for high-resolution imaging without using any radiation. The core of this is state of the art imaging which detects and processes a break in the established thermal balance between the clothes and a hidden object. The IR camera detects the heat radiating from even a tiny object, producing a dark/light shape. It is irrelevant how long an object is concealed under clothing as a new temperature imprint is created every time it is scanned. Using IR, the rays don’t penetrate beyond the clothing so there are no privacy issues.