[ubuntu] laptop over heating when AC disconnected

view full story

http://ubuntuforums.org – I have Ubuntu Jaunty updated to the latest updates it's just a few weeks that I have installed it (before I was using Vista) I noticed that the laptop overheats when I disconnect the battery charger. The system monitor utility shows that temperatures reach 80 C whereas when mains power is attached temperatures reach maximum 50 C Is there anything I can do? (Hardware)