Iphone Heating issue

I purchased iphone 12 two weeks ago and it works fine however when i put it on charging and during charging if i have to use it like watch youtube use instagram or do any other activity it heats up considerably, but then if i leave it locked and on charging it charges fine without heating up.While normal usage during the day it works absolutely fine and battery lasts easily for the entire day.Is Heating while using the phone on charging mode Normal? Thanks!