no more power button to end calls???

I use this app almost every night in a call with a good friend, and we usually end up falling asleep while in a call together. My issue is that whenever I press the power button to turn my phone off, the call ends. I would like to be able to shut my phone off because my phone staying on all night while on the charger makes it overheat and when I wake up in the morning the phone battery will be low. Can this be fixed?

strevino1252 about Hangouts, v21.0.0