Why does my Lumia 638 produce heat when it is charging?

[Ankenapalli Veera Reddy]

About Lumia 638

I bought new mobile Lumia 638. When i am charging my phone heat is produced in backside.Is there any problem in my device.If any problem how to overcome this problem.

 

[Intense Soul]

Re: About Lumia 638

I never faced this kind of problem on lumia 638. Is the heat very frequent? like is it getting heated up when you charge the device and simultaneously using the device?