@siwywdc: Some overheating can be expected, especially during extended use, and when using power-intensive apps and games. Please can you take a look at the steps below in an effort to improve the issue?
- Shut down all background apps when not in use via the Recent Apps button
- Settings > Connections > More Connection Settings > Nearby Device Scanning > Off
- Turn off Wi-Fi, Mobile Data and Bluetooth when not in use
- Head to Settings > Battery and Device Care > Battery > Power Saving Mode > On, and check the additional options below
- Go back and select More Battery Settings > Adaptive Battery > On > Enhanced Processing > Off.
Please can you follow the link below and run through the series of questions/troubleshooting steps, to see if this helps at all?