Like everyone else said, you can get any surface temperature you "scan". Just remember, that you cannot get a reading "through" any type of material. If you try to scan through glass, you will actually end up reading the surface temp of the glass.
I've tried a number of temp. guns and have finally found my personal favorite. It is a little spendy, but is completely worth it in my opinion.
It is the "RBI 412L" I found it at Reptile Basics website. I'm not sure if anyone else has something similar. It costs roughly $60 but after trying several other models through the years, this one is worth every penny in my opinion. It has a 12:1 distance to spot ratio, which means that at 12 inches away you are scanning an area of only 1 inch. Plus it has a laser pointer and large display.