It is high, but not to the point where you're going to kill your NB. Try and get some airflow over the chipset if possible or back down the NB voltage if you're concerned. Depends on the chipset though, my RD600 runs a fair bit warmer, but it's due to a chipset heatsink that is far from flat.
Is it worth it to you to re-apply any thermal paste under the NB heatsink and see what happens?