2 “Don’t Use Your iPhone When It’s Charging”
This may be a well-intentioned myth, but it’s still patently false. There are cases of smartphones catching fire or electrocuting people, but these are not widespread occurrences. And they common have to do with other factors, like cheap chargers.
In the vast majority of cases, it’s completely and totally safe to use your iPhone when it’s charging. Just make sure that you’re using a good-quality charging brick and adapter. For added precaution, keep an eye on the iPhone’s temperature if you’re streaming video or running CPU-intensive apps.