Can I continue to use Iphone XR when it’s getting warmer and warmer , and even hot ?

I noticed when I was doing video calls on Skype , the back if iPhone is getting warmer and warmer , and even to the point of hot , then I had to stop the skype call out of concern of heat permanently damaging my phone battery and phone itself , do we have any standard practice here like when to stop using and let it cool down ? Or heat up because of using skype video call doesn’t even affect the battery or phone in a bad way ?