(Disclaimer: I am not a physicist, nor even a scientist).
The thing is, people talk about detecting or seeing "IR" as if it's a single entity, much like how they talk about seeing or detecting visible light. However, "IR" covers a much, *much* wider range than visible light (*) and "near" IR- which is just outside the visible light range- arguably has a lot more in common with visible light (and how it can be recorded) than the "far" IR closer to the other end, which is used in heat-sensitive cameras.
"Near" IR can be recorded on most regular digital cameras if the IR-blocking filter has been removed (i.e. they're sensitive to it by default and it has to be filtered out), or even if the IR-blocking filter is weak (some older cameras were like this). It looks interesting and different, much like how someone who can only see green or blue light might feel when seeing a photo of the red part of the spectrum. And it can be used for night vision if it's used with a near-IR light source (which people can't see, but is still easy to detect with unfiltered electronic sensors).
But it won't give you "heat vision" unless the thing you're viewing is so hot it's almost- but not quite- visibly glowing red (**). The wavelengths of IR given out by things at normal temperatures are much lower (i.e. closer to "far" IR) and require different detection equipment- the problem being of course that they traditionally had to be cooled to avoid detecting their own heat being emitted.
And in fact, IR-based "night vision" could refer to (at least) these two very different solutions- *either* the "easier but requires IR illumination" near-infrared device one could theoretically do with modified off-the-shelf camera sensors or far-infrared heat detection (i.e. detecting the objects' own heat).
Anyway, it sounds like this report is describing "heat vision" far-IR detection, since it mentions the problems with that, and how it gets around it. Just bear in mind that "infrared vision" could potentially refer to either near or far IR, and they're different kettles of fish.
(*) Visible light covers wavelengths from 380 to 700 nm (i.e. approx twofold difference from the shortest to the longest), IR covers from 700nm (0.7 micrometres) to 1mm (1000 micrometres), a factor of well over a thousand times difference!
(**) AFAIK this is as per:- http://en.wikipedia.org/wiki/B... , i.e. as something gets hotter, the frequencies it gives off generally increase, from far-infrared to near-infrared, to red and then to yellow. (Yellow becomes "white hot" rather than blue because it's still emitting significant amounts of lower frequencies). So if it's almost- but not *quite*- red hot, it'll be emitting signficant amounts of near-infrared. Much cooler, and the radiation will be of lower wavelength.