I should probably add, valheim and only valheim has caused overheating problems for me, i have played plenty of other games both higher and lower on the requirements and non have given trouble.

Examples, FTL, Enter the Gungeon, Conan exiles, Soul Calibur 6, Witcher 2 & 3, essentially a full gambit of game engines and only valheim causes the problem. It's definitely some poor coding on the valheim's part, everything else is completely stable on my machine.

As for hardware fans etc, cooling is decent my GPU reaches 35C under load and rarely even kicks on the fans. CPU is a similar story stable no matter how i use it, expect with valheim.