This is made worse by the inability to see distinguishing surface details in long-wave infra-red light. You just see the value of the temperature, not lines and shapes. In the sample below, it's clear that we're seeing a human. But what's going on with his lower face? Is that a beard? Is his face partially covered? Is he perhaps holding a camera or a rifle? Or is he drinking something cold? And just what is happening in the background?
The worst aspect is that humans don't have any kind of "infravision" at all. So if the rest of the party is making do with their "infravision", are they leading along one or more blind humans?
Or does the torch-weilding human wreck everything for the other races by drowning everything in "hot", flickering light?
I've decided to get rid of it. I don't mind if non-humans have short-wave infra-red sight capability where there is natural light (e.g. in twilight, or by the light of the moon and stars). But since neither short- or long-wave infra-red vision really makes the game more interesting, and in fact adds distortions and problems, I'm scrapping them.