Running hot since kernel update -

[Chris Mohler]

Stating the obvious:

You should ensure that the machine is as dust-free as possible.  Run
it with the case open and make sure all of the fans are running -
case, cpu, power supply, etc.  The timing with the kernel upgrade
might be coincidental.  The only way I can think of to check would be
to boot the previous kernel and see if symptoms persist.

Good luck,
Chris