How to reduce Nokia Lumia 520 heating?

I bought my Nokia Lumia 520 six months back. Things were good when I purchased. Recently I am facing heating issue in my handset when I use 2G or 3G internet connection. I can't bear the heat when I was in call. It heats up more surrounding the camera. Fortunately all users having Lumia 520 are facing exactly the same issue. So there is no complete solution for this problem but I came with solution that don't completely solve the issue but it is temporary.

My dumb solution - Buy pouch

First thing I did is I bought a purse-type pouch. It means even if the phone gets heat up I won't be able to sense it. I know this solution is lame. But I have no other solution and experts from Microsoft and Nokia are reporting it is usual in electronic device. Another thing I found is, restarting the mobile reduces the heating time. If your mobile gets heat up after 20 minutes of internet usage then restating your phone makes your phone heat up after 35 minutes. It is because your RAM will be filled with process and services running all the time. Restarting will close all the process and service which in turn close all the inactive ones. This way you can improve the phone heating time.

Answers in Microsoft and Nokia forum - It is normal for a smartphone

I am proud that nobody came up with my idea instead they were arguing it is normal in electronic device. Some users answered like Lumia 520 has well packed plastic panel which doesn't dissipate heat. Abnormal heating issues like if you can't even hold in hand then you can report to Nokia service center it seems. The causes of heat listed in official forums made sense. One user gave a example like you are holding a mini-computer in your hand and how you are expecting not to get heat? He concluded saying that phone is warming not heating.