Hence my post Skadi - the video is a very pretty view of an airfield approach in the dark but the question is ..when would you use FLIR to make an approach?
If the weather is on or below instrument minima, the FLIR won't see the ground for the reason you mentioned so you will have to divert anyway.
If it is for night use then you need to ensure that you only use it when you have good conditions for IR - no recent rain, no thermal crossover etc - you are far better off with normal instruments or NVG. The Apache uses millimetric wave radar which can see most things (not wires unfortunately) but that is a rather expensive option I think.