If you want to try to find a water leak behind a wall, a person hidden in the bushes at night, or identify passengers with a fever passing through a checkpoint, thermal imaging is the technology for you.
But until now, that was only if you've got a very big budget. Cameras equipped with the technology -- which measures differences in temperature on the electromagnetic spectrum -- have long been too expensive for everyday use. Most cost well over $1,000, if not double, or triple that.