@Loy1: You should expect the phone to heat up a little during periods of extended use, or when using power intensive apps like games, streaming services and social media, however it shouldn't be too hot to handle. Please be assured that you will see a notification if the phone becomes too hot, and it will power off in some instances as a fail safe in order to cool down. If this doesn't happen then please don't worry.
To troubleshoot the issue, please try following the steps below.
1. Head to Settings > Security and privacy > Auto Blocker > Turn this off temporarily
2. Open the Phone app > Dial *#9900#
3. Scroll down to 'Batterystats Reset' and tap to select.
4. Exit the menu by tapping the Back button in your Navigation bar, then head back to Settings > Security and privacy > Auto Blocker > On.
5. Press and hold the Side button > Restart.
The benefits of the above steps won't be instantaneous, however your phone will enter an optimisation period similar to when you first started using the device, and learn your usage patterns to improve your overall battery life.
I also recommend taking a look at the links below, which will walk you through further steps that you can take to optimise the battery life on your device.
https://www.samsung.com/uk/support/galaxy-battery/optimisation/
If an issue is happening immediately after an update it's also a good idea to make sure all of the apps are up to date too, and to carry out a 'wipe cache partition' to refresh the software:
1. Power off your device, and wait for your device to turn off completely
2. Plug-in a USB-C data cable connected to your PC
3. Press Volume Up + Power buttons together until you see the Samsung logo, then release. The device will boot into Recovery mode
4. Use the Volume Up and Down button to navigate through the menu, and the Power button to select & confirm an option
5. Navigate to 'Wipe cache partition' , select & confirm it, and follow the step it advises
6. Navigate to ‘Reboot system now’ and select it. Your device will reboot as normal.
