FWIW, infra-red is not the most stable of films, and the expiry dates seem to be about half those for regular films. The advice I've seen (and observed) is to keep it refrigerated (not frozen for some reason?), dont leave it partly exposed in the camera for any length of time and process it right away.
I wouldn't throw the films out myself (I hate waste)...particularly if you have more than one, try one out on some unimportant subject. All you can lose is a bit of time and a few pence worth of dev and fix.
Assuming the film is 36 exp, I obviously wouldn't spend time taking 36 different subjects! Maybe three or four different subjects maximum, bracket the exposures on each one and perhaps try different filters.