A try a forced-restart may be beneficial following a system update - as this will often resolve unexpected software and hardware issues:
- On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
- On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.
Be aware that following a major update, your iPad will be running background tasks - including re-indexing. This background activity will temporarily appear to reduce battery life and system performance - coincident with higher CPU loading and heat generation. The process make take several days.
Whilst you iPad may become very warm, it should not be too hot to comfortably hold. Sometimes a process can get “stuck” and generate unexpected heating of some internal components. The forced-restart will usually resolve issues of this type.
If you continue to experience difficulties or have any concerns, you would be well advised to seek assistance directly from Apple Support. The Get Support link can be found at top-right of this page. Alternatively, you can initiate and manage a support case using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:
https://apps.apple.com/gb/app/apple-support/id1130498044
As a further alternative, you might visit the Genius Bar at your local Apple Store - where the technicians will be able to test and assess your iPad.