Originally Posted by
dougmc
Unreliable. As I already mentioned in this thread, a 100 degree F body doesn't emit much IR, especially compared to the things around it that are only a bit cooler. You won't be able to pick that up at all during the day, and I'm guessing that if your headlights illuminated the deer that the IR reflected just from that would wash out anything that the deer itself emits.
I don't know much about IR technology, but if what you're saying is true, then it doesn't seem too useful in places where it gets very hot, like the entire southwestern region of the US during the summer. And, at night rocks and road surfaces retain their heat longer than their surrounding and it seems like it would give off a confusing heat signature.