On weekends we do energy audits for churches and non profit 501Cs and this morning I was busy in a small Catholic school all by myself going from room to room with the big blower door running. Infrared energy audits focus basically on exterior walls looking for cold air infiltration. The bluer the color, the colder the temp, and red is hot, and yellows and oranges are warm areas. We never bother looking at interior walls since everything on the wall is the same temperature and the entire wall will be the same color, unless a cell phone charger is plugged in, or a heater vent, even a GFCI outlet.
I finished scanning an exterior classroom wall and turned around towards the inside wall, WOW was I shocked to see the only thing warm on this cool inside wall was a little Jesus on the Cross wall hanging. I went back later and it was still showing up with thermal imaging. I guess I wasn't alone in the building today!