My iphone 12 is heating too much

I too had a similar issue few months ago on my iPhone 12 Pro bought two years ago from Apple Store in the USA.

What I did is given below

1. Took a backup on iCloud (Which I do regularly)
2. Logged out of the Apple ID
3. Erase --> Erase iPhone - Apple Support (IN)
   1. Keep eSIM Data was the option I chose (See the pic)
   2. .
4. Set up my iPhone and restored it from iCloud Backup
5. 

I continued to have the same issue with the heating.

I repeated the above steps but this time I did not restore from the iCloud Backup. I set it up as a new iPhone.

Waited... There is no heating issue.

Conclusion.:

• This does not suggest any hardware issue!
• This is also not an iOS issue
• Some Apps or iPhone storage maybe heating up the device.
• This is not the iPhone Cover or Charging able issue as I had used the same cover and cable while doing both the above processes

Action Plan:

• I will now slowly get my all data back one by one.
• Using the elimination process I will try to find out which app or settings were causing this...

It has been many months since then I have got back 70% of my apps and the heating issue has not returned. Probably the rogue apps were not used now.