Device becoming very hot and laggy when play game

[Cawai]

My device (xperia x) getting hot when charging. Temperature is around 40 °C and 41 °C. I have installed latest system update and I also make factory reset. After reset, device getting faster but the temperature remain the same. When I play game temperature rise to 42°C and 43°C and the performance goes down and laggy in game.

[Uliwooly]

@Cawai

I know how frustrating that is, there's nothing wrong with the phone, that's how the phone prevent hardware damage.