Heating is one of the dreaded complication s of Samsung galaxy S II, how many blogs u might have searched believe me I know I have gone through it myself
So how did I overcome it for this you should know what is is causing this overheating .The answer is simple it is your Android version the gingerbread 2.3.3 or 2.3.4.
What can be done about it is first and foremost update your Samsung kies on your PC to the latest version.
Next step is connect your phone to your PC via kies using the wire you received with your phone.
Now back up your
2. MESSAGES (sms)
3. CALAENDER ENTRIES
4. ANY MEDIA like PHOTOS ,VIDEOS
Now as you know it will try to check the firmware say YES to the new firmware update and follow the given instructions on the updating portal. Most important is to keep your phone fully charged before you update.
So AFTER ABOUT 1 OR 2 HOURS (depending on your net speed) your firmware will be updated to 2.3.6 (this is the latest untill now in India and asia.). I know Ice cream sandwitch update is on its way but those of you facing the heating problem I am sure its difficult to wait.
The heating problem was cured on my phone.
( Warning you are solely responsible for updates so use caution)
you are one of those who has updated already you would have felt a drastic fall in temperature on you SGs2. How ever I did see many people complain of little heating while charging. so what I discovered was the heating was only present in the battery so I bought a spare battery and a charger which was available in the market which charged my battery out side my phone. the trick is if you charge the battery while your phone is off it will rarely get heated so if you find the charger in the market its fine if not switchoff the phone while it is charging plus u will see the phone charges faster
Another thing I discovered that if you u cleared phone cache often killed unnecessary apps the heating decreases. Do restart your phone once in a day