#1 You should totaly check your Fans and cooling elements for extreme dust and maybe pet hair if you have any. (Please be carefull with compressed air or vacuum cleaners. Make sure that the fans won't rotate while using those. Because a fast rotating fan works like an electro motor and will indicate voltage on your hardware. You do not want that!)
#2 Could you specify your Hardware build please.
CPU, Graphics card, RAM (or model of your PC/Notebook and age)
#3 Check your Task Manager, how much CPU Usage do you have while idle and running the client?
#4 If it is your graphics card which overheats, it may help if you UNcheck “enable advanced graphics” in the settings and restart the client.
greetings
Elena