Talking of heat, my son's laptop (as mentioned above) started running hot and locking up. Turns out the fan outlet grill was full of fluff - something to do with having 3 cats I suppose! Had to remove the bottom cover of the laptop to get at the fan outlet but having cleaned it thoroughly the PC now runs very cool with no lockups.

Laptop power supplies can run hot in normal conditions, especially if they are only just powerful enough for the computer concerned, so it may not be a fault as such. However too hot to touch does sound rather suspicious! Nevertheless there are a lot of generic laptop supplies out there so it shold be possible to get an "over rated" PSU, which ought to run cooler.