While the use of night vision goggles doesn't seem to be a particular boon during the first of two areas featured in this video, we'll let Lead Game Designer J.P. Cambiotti explain some important tactical uses of NVGs in Rainbow Six Vegas 2
"The ability to use night vision goggles (NVG) is a feature that returns from the original RS Vegas and they remain a really important gadget in many areas of this game. Night vision goggles allow you to see much further than your thermal imaging system. In RS Vegas 2, you will have plenty of opportunities to use night vision, specifically in the Nevada desert where night time means everything is pitch black and there are many long lines of sight to cover. You can keep your night vision on throughout most of the map, or use it when you get to certain spots that require you to see more details or enemies that you could not see without them. The ability to see well at night also allows you to play through the map in a more stealth manner. Your night vision goggles are specially adapted to work with your snake cam, giving you a great tactical tool. If you're using the snake cam and having trouble seeing, turning on your NVG will allow you to observe properly, then plan and act according to the best strategy. You can also use your goggles combined with a rifle scope, so seeing and sniping at long distances in the dark are simplified. Tip: You can use your night vision to properly navigate very dark areas, but you can switch to your thermal vision to accurately identify enemies in the vicinity."