iPhone 6s heating and lagging issues after iOS 15.8.3 update
[Edited by Moderator]
[Edited by Moderator]
It's not always the iOS update's fault! Many things can cause phone problems. If you tell people you think it's an iOS update, it might make it harder to fix or find a solution for the real issue.
Remember, the right question often leads to the solution! Please look in the right direction.

iOS updates aim to enhance user experience, boost security, and fix bugs rather than disrupt core features. The majority of the issues after updates might stem from underlying, unmentioned factors. Updates won't typically alter personal data but may refine settings or features. Backup before major updates for safety. Review Apple's update details and backup advice for a smooth process.
Kindly consider checking your settings and addressing any device issues before attributing the issue to external factors. This could be a pure coincidence that the iOS update affected the iPhone functions.
Before initiating a standard iOS update, it's advisable to create a backup. Have you completed this step? If yes, proceed with the restoration from the backup.

See what each update does: About iOS 18 Updates, About iOS 17 Updates, About iOS 16 Updates, About iOS 15 Updates, About iOS 14 Updates, About iOS 13 Updates, About iOS 12 Updates, and so on...
It surely is not after iOS update because...
I conducted a thorough search of this forum and uncovered numerous posts detailing similar issues across various iOS updates. This suggests that iOS updates may not consistently be the root cause. Below are a handful of examples extracted from the search results:
The links I've found suggest that the reason for battery drain may not be solely due to iOS updates, but rather, it could be influenced by how an iPhone is utilized.
Please note that this is a public forum, so when attaching a screenshot, please avoid including any personal credentials such as IP addresses, card details, email IDs, Apple IDs, IMEI numbers, serial numbers, phone numbers, order IDs, invoices, or any identifiable location information if you are sharing a map.
iPhone 6s heating and lagging issues after iOS 15.8.3 update