Where is temperature sensor on iPhone 5?

Hello. I have new iPhone 5, which was manually damaged (don't ask me how). To make it work again I've replaced lightning connector, battery and now i can turn it on and charge it. But now i constantly see message of Temperature overheating (iPhone needs to cool down before you can use it) and i can not use iPhone (except for emergency calls). iPhone's screen is turning down every 5-8 seconds so i have to turn it back on by pressing Home or Power buttons.

When i connect it to iTunes iPhone begins to sync but never finish it because when screen is turning down the sync stops too and iPhone disappear from iTunes (like when i manually disconnect USB cable)

Probably there is a problem with temperature sensor and i have to replace it too but i can not find it. Please help.

Not sure if it helps but i've lost a metal shield which covers LCD's cables.