iPhone 16 Pro Max is overheating and battery is draining fast

It is true that for about 4/5 days after any update, you should experience heat and battery drain as you can see in this support article provided by Apple. If it has been longer than that, continue on with the next steps to follow.

About Apple software updates - Apple Support

Have you tried removing those 3 apps and compared your results to see if the apps are causing your problem?

Apps are updated independently of the OS and with Meta apps you will see them update as much as 12 times every month and some of those updates have been problematic. You can use those services on the web in the meantime while testing as Safari will not have the same amount of battery drain as those apps do. Meta has already been called out for their data harvesting on your device that produces both heat and battery draining. I suspect you also see Background Activity in your Battery Settings for those apps, meaning they are draining your battery even when you are not using the app.

If you determined the heat/battery drain goes away when the apps are not installed, then you will have a better idea how to proceed and what you are willing to accept for the apps you have installed.

Then your next step would be to make an appointment at the Apple Store / Genius Bar or take the phone to an authorized Apple service shop.

You can find list of authorized shops in your area by using this link:

Find Locations

In some cases, Apple Support may be able to check and test your phone remotely, but this type of check does not reveal as much information about the battery as an in person visit. Contact Apple Support if you want to see if they can test your iPhone remotely.

Support

Good luck.

Your iPhone 16 Pro Max heating up near the Camera Control button and draining battery fast during 8 hours of daily Instagram, YouTube, and WhatsApp use is likely caused by background indexing after your recent update, a rogue app process, or heavy thermal load from the Camera Control hardware sensor capturing touches continuously. 

Have you tried to force restart your iPhone to see if the issues persist?

1. Press and quickly release the volume up button.
2. Press and quickly release the volume down button.
3. Press and hold the side button.
4. When the Apple logo appears, release the side button.

Depending on where you live, Apple may be able to run remote diagnostics on your iPhone. Contact Apple Support for more details.

Support

Other than that, there is not much that you can do until you can have the battery checked and tested.