From: Joerg Sonnenberger <joerg@britannica.bec.de>

  No, it isn't. Think about a Dual Xeon with 4 cores overall.

Sorry - I didn't go read the code in question before commenting.  After
looking at it, I don't understand if this is dealing with something that
has a single temperature sensors for 2 cpus on the same chip, or a
temperature sensor per cpu.  I have gotten the impression that using one
cpu and not another leads to one being hot and the other not, at least
on my T60 (Core Duo).