This step is not required, but can make a huge difference.
Step 1 — Noise ReductionThis is actually an OPTIONAL Step – create a duplicate layer of you background for noise reduction and general retouching. For noise reduction, I have been very happy with the Noise Ninja plugin. You could also use the built in noise reduction filter in Photoshop. Noise can be pretty apparent after you are complete with image editing, it is not required, but might make the image look cleaner. However, some people intentionally add noise (grain) into their IR images as it is more authentic looking.
You don't have to run noise reduction on your image, but you will notice a big difference if you want a 'clean' looking file. Once you are done with processing, the noise may become very apparent. Honestly, I have not had the greatest results with the Elements 3.0 noise reduction filter, but you might. Otherwise, use your favorite plug-in. As mentioned above, I am really happy with Noise Ninja.