Mike,

I'm only peripherally aware of the LAR-IAC data particulars but Im guessing youve got a combination of NearIR/Green/Blue or NearIR/Red/Green/Blue.

If confirmed, you can elaborate your answers to your clients using the following sample vegetation spectral graph (see below). The pigments (chlorophyll) vary from plant to plant but the following spectral graph represents how floristic reflectivity/absorbance can be characterized. Check the specs on the dataset to see what range of IR it covers (typically digital covers a more refined range within 0.76~0.97mu).


So your IR is truly IR. However if I'm right, the rest of the bands are nothing more unusual than what you see in true color. 

As for heat, thermal radiance is much higher up the EM spectrum (<10mu) so the answer in short, is no.
 

For a crash course in remote sensing, try http://rst.gsfc.nasa.gov/