After playing Minecraft for about 15 minutes my computer shuts down.

After installing the new minecraft launcher, it seems that starting yesterday everytime i would play minecraft, after 15 minutes or sometimes less, it would completely shut down my computer. I have tried uninstalling, reinstalling, deleting all the minecraft files and even restarting my computer but nothing works. Switching to another version besides 1.8.9 doesnt seem to work. I make minecraft youtube videos, so it is a pretty important thing for me to fix this.