Hey even I have the same laptop. The problem here is that our laptop contains 2 graphic cards 1.AMD 6630 2.Intel HD 3000
Somehow, by default Ubuntu keeps both of them running, even if only one is used, that leads to overheating.
The solution is to turn off one graphic card.Here I show how to disable ATI card, and just use the Intel HD graphics.
Enter this command in the terminal to check the graphic card status

cat /sys/kernel/debug/vgaswitcheroo/switch

you will get o/p like

 0:DIS: :Pwr:0000:01:00.0

 1:IGD:+:Pwr:0000:00:02.0

here DIS=AMD card, IGD=Intel card.
Pwr on both the lines means that both are powered.To turn the DIS off, enter

sudo echo OFF > /sys/kernel/debug/vgaswitcheroo/switch

check the status again. you should get Off on the 0:DIS line.This means only the low-power intel card is running.Use you laptop for an hour or two, and feel the difference.
If it is indeed running cooler, to make the changes persist even after reboot, edit the rc.local file.

sudo gedit /etc/rc.local

and add the following line above exit 0

echo OFF > /sys/kernel/debug/vgaswitcheroo/switch