I’m not sure if this is helpful, except for the general idea of seeking technical support from Apple.
Yes, technically, you’re right. What is commonly referred to in this thread as “overheating” is not technically overheating in the tech sense, where the system shuts down to protect itself. It’s just the device getting warm or “hot.”
However, that’s mostly arguing semantics with little value to the people experiencing issues.
More importantly, you seem to suggest that only the situations you described will cause a degraded user experience, which is not true.
Before the iPhone reaches the infamous “I need to cool down” screen or a more serious emergency shutoff, it will start throttling to prevent that from happening. This can result in a noticeable difference in performance.
That said, something like this happening occasionally is nothing to worry about. However, if it happens regularly or significantly impedes your daily usage, I highly recommend visiting your nearest Genius Bar or contacting Apple Support.
I also suggest people reach out to Apple if the issue persists even after replacing the device. This provides Apple with valuable information about real-world issues and can help resolve design flaws, as some have speculated. If the issue persists across replacement devices, Apple may even upgrade the customer to a newer model.
In any case, Apple will always take care of you, but you need to be proactive if the initial attempt at solving the issue doesn’t work.