Q: After update iOS 8.0.2 my iPhone 5s is very hot in back side when internet browsing

Hi Amar795001, 

Welcome to the Apple Support Communities!

I know these types of issues can be frustrating, but please read over the attached article about iOS device operating temperatures. 

Keeping iPhone, iPad, and iPod touch within acceptable operating temperatures

When using the device or charging the battery, it is normal for it to get warm. The exterior of the device functions as a cooling surface that transfers heat from inside the device to the cooler air outside.

Have a great day, 

Joe