I have acces to a Xperia Z2
it gets very hot with 4k recording but almost all else it gets a tiny bit warm at the most
4k recording # HOT
Gaming - cool
HEAVY gaming - warm
Everything else - barely warm at the most
Trying to play 3 games at once using mods - suprizingly just warm
52 degrees Celsius is the highest i managed to get it to thus far, aside doing things that "normal people do"