Melissa
if you are talking the bar on the right hand side that is a thermal scan ... body heat will be red or bright yellow depending on the distance but something carried like a firearm or knife of any type will only reflect heat and will show up as a cooler color. Apparently the scanners also do thermal.

I will use one for finding bigfoot I will ... a Flir Thermal so if the critter is hiding in the brush I will see him