I don't know about the Army, but on USS Milwaukee as early as '90, we had a portable thermal imager that was designed to help our firefighters detect hot spots in a smoke-filled engine room. I think the technology has abeen around since the mid-80s.
It was about the size of a large radar gun back then. I know that more recent thermal imagers are about the size of a small digital camcorder, and are leaps ahead in resolution and sensitivity.
Davy Jones
"Frightened? My dear, you are looking at a man who has laughed in the face of death, sneered at doom, and chuckled at catastrophe! I was petrified."
-- The Wizard of Oz