They're not implemented yet.
-geever
i remember using ir goggles, i think it was in 2.2.1, and also in some 2.2.3 dev version.
i put them in the hand slot and used scan, and then clicked in the direction where i wanted to see through walls, more or less like a weapon.
actually i think the game became much less interesting that way, as the unknown was removed from behind the corner.
on the other hand, checking all houses and rooms can be tedious.
i would prefer some general value that would indicate which direction to look for aliens, maybe some radiation counter that wouldn't show any image at all, just cold--warm style thing.
and ufo defense style motion scanner which is more or less the way they had it in the "alien" movie is nice cliche imho.
