Help! PS Vita Heat Problem?

[Erz]

I have PS Vita 3G, each time I play game offline around 10-20 minute, the back of my Vita is starting to get warm and the next 40-60 minute its get heat (the same heat like someone get a fever)

When play online for 40-60 minute, connection is disable because the System is Overheat.

My PS Vita setting is
Brightness = 50%
System Music = OFF
Auto Update = OFF
Mobile Network = OFF
WiFi Network = OFF
Bluetooth Connection = OFF

Is this normal? Everyone have this same problem to?

I thank you for your answer in advance

[Azrial]

I don't have the 3G version, only wi-fi, but it doesn't sound normal, I can play for 4 hours+ fine, with no heat increase, take it back to the shop if I was you.

[Erz]

Yes, I've heard that wi-fi model don't have this problem

Hopefully people that use 3G model can tell me about this