Nope, apparently according to the latest research, zombies are known to ART (Assume Room Temperature) and as such would not stand out from background temperature, thus no differential of import. .
That depends on the type of zombie. I Am Legend has fever zombies -- the zombie virus is postulated to elevate body temperature, creating a super fast zombie.
Anyway, $1,000 is still a lot of money for something with limited application. For the average civilian, I can think of two situations:
-- Finding wounded, unconscious people in the dark, or perhaps children too scared to cry out.
-- Identifying threatening individuals in a dangerous situation.
In both situation you need stealth for some reason, otherwise you can just use a regular flashlight. Any other uses?