wrote:

You could make an IR pass filter (daylight filter) from a piece of
exposed film negative. Put it in front of a black and white TV camera.
Then point it at your test subjects. The ones that are the brightest
are relecting the most IR and should be the coolest.


Or better yet. Get one of the 'security cameras' from Harbor Freight.
Most CCDs are really sensitive to IR, so much so that they have to
include a filter for it to get any sort of decent picture. The 'night
vision' security cameras are really cheap cameras without the IR filter.

So I've been told.

--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."