How long have you used this laptop for, also when does the temp get to those levels, when not doing anything or gaming, watching movies etc? It could just be accumulation of dust that is causing more heat to be generated. Or it could be due to prolonged use the thermal paste of CPU isnt working as it first did, coupled with dust build up is causing high temps. Either way you should first just try a quick dust removal clean up by opening up your laptop a bit, you can get canned air to remove the dust quicker and see if that helps. If it doesnt then new thermal paste might be needed
I know I am replying very late, but it shuts down at about 120 degrees, according to realtemp 3.7. It begins throttling at about 110. (But only gets this hot when playing CoD4 or other 3D games on a +30 degree day). Normally at about 85-90 just internet surfing. Right now at 80 air temp about 15-20 degrees approx.(But it wont go past 655 Mhz for some reason, so this is a bit weird, normally goes flat-chat at multiplier 10.0x but today only 5.0x)
P.S. I AM using the laptop on a hard surface, with 3G enabled and surfing.
1. What unit of measurement are these reports in (Celsius or Fahrenheit)?
2. The best ways to reduce temps are to clean anything clogging the fans and/or heat sinks. Use compressed air to blow out the vents. It's ideal that you use something to prevent the fans from spinning when you blow out the system, otherwise you could damage the fan bearings. Reapplying new thermal compound where necessary may help also.
And always make sure the vents are not blocked by anything external either. It's best to have the laptop raised slightly if the fans draw air from underneath.
Degrees Celcius. I do not think it is hardware problem, as Ubuntu 12.04.4 LTS has never shut down from over heating. Fan is spinning properly, and I have had a superficial check for dust, but it seems alright