Probably a bit of both. Mine has substantially cooled since last week or so when my phone got so hot after using Lightroom I was worried it would be damaged, completely autrageous temperature. Never noticed because I wasn't touching the phone I was using the S Pen in a kickstand case. Optimising my apps through galaxy labs, deleting old apps I didn't need downloading the latest versions of stuff I think all helped me.. If you haven't already downloaded galaxy labs which has a thermal battery and CPU checker that you can toggle up or down, I think it throttles the CPU when it reaches the temperature level you choose. Though the data gives no numbers just emojis and partially guessed reasons why it got so hot. There's more likely a better app to track temperatures but I'd for sure download that. What's version of software have you got installed?
