go to setting ....look for 1 hand operation

while u using it will become hot.

For my case:

when i call for more then 5 - 8 min , my face will like burning.

I dont realize it was a problem until i send in for the camera problem.

there will be some condition when getting hot, example ur phone will hang, and when ur phone is in sleep mode when wake up it require a few sec to on the phone.

my phone in sleep mode by pressing the side lock button on the right, when awake the phone by using either the right button or home button it require 3 or more second to awake.

For new users and to be user - the SGS II operating temperatures is higher than most other Androids, simply because it is dual core and its thinness transmit heat easily. Some users like to use the word " hot" - I'd said is warmer than normal. The word hot connotes a feeling of uneasiness and a possible burning effect on your skin, which it will not. Most users I believe will use some sort of casing or backcover - these will reduce the effect

If you have been using single core Androids 1 GHZ models before - you will not experienced the " hotness" as a serious concern, I'd say generally is about 2-3 degree centigrade more. Those who are coming over from say Blackberries and Symbian will feel the difference more obviously