LeagueClientUx

My computer is having trouble with LeagueClientUx.

Whenever I am in champion select, I can hear the fan turn on, as if the computer is overheating. This is confusing to me because my fan usually doesn't even turn on while I am in game (the only exception being when I have a lot of tabs open). Also, unless I run champion select in the background (which increases the chance of me accidentally not banning or picking a champion), LeagueClientUx will crash my computer, causing an automatic restart. Has anyone else been experiencing similar issues? Does anyone have a fix for this, other than constantly switching to legacy client?

I am currently operating on a MacBook Pro Retina 15 inch.