How Hot Is My Tablet?

I had a weird and disturbing shutdown incident on my tablet PC (a Lenovo X61) a week or two ago, which got me many screens of ominous looking text before it finally booted up properly again. Poking at it afterwards, it seemed to be running a bit hot, and it doesn’t seem like there’s a fan running.

This turns out to be a non-trivial problem. It’s my personal machine, and out of warranty, so the folks in ITS can’t touch it. And the local computer repair place that was recommended says that 1) Lenovo uses several different types of fans, so they can’t say what part they would need without opening it up, and 2) once they know the part they need, it could be a couple of weeks before they can get it, depending on the part, the source, and the phase of the moon.

Given that, I would like to confirm that this really is the problem, and not just me overreacting to some random glitch. It ought to be possible to do some better diagnostic than “I think I remember more air coming from this spot than I’m getting now,” but if it’s included in the control panels or Lenovo options, they’ve hidden it well.

I know this can be done, though, so somebody tell me how– if I need to install some third-party diagnostic thing, what is it and where do I get it? It’s a Lenovo ThinkPad X61, running Vista. I’m looking for something to tell me whether the computer is, in fact, in danger of overheating, by some method short of leaving it on all night and seeing if it still runs in the morning.

(If you tell me to get a Mac, or to switch to Unix, I will ban your IP address.)