I have a PowerBook G4 1.25Ghz (15" Aluminum). I've had it for about 3 and a half years now, but while I've had it, I've never used it much for more than a couple hours at a time. Today, I was at a friend's house using it for about 4-5 hours now, and I noticed it was running very hot, and the fans were running at full blast. So, a couple questions.. is this normal, and should I worry at all about this? Also, is there anything I can to help cool this thing off?