How warm does the LS PCM get?

[beeman]

I have room for the engine PCM (and throttle control unit) behind the passenger seat in the cockpit, and I would prefer to put it there to make some more room in the engine bay. Does anyone know if they put off much heat to where it would warm the cockpit significantly?
Looking at ls forums, some will mount them under the dash, but others say they are hot to the touch when running.
Thanks!