My mac heats when playing on web flash games even a simple Flash games.
My baby loves play flash small games on Google chrome browser its www.friv.com web site with baby small flash games and my Mac goes crazy during play :) Heats and coolers get louder and louder like he is starting to fly :) i also realize when i play integrated Mac app "chess" ( which comes with mac apps) its also do the same things.
i do not talk about Photoshop as i know its not and easy app for mac... but flash games?:( maybe its normal ?
mac is not old, its always clean and always in leather pocket, so dust is not reason.
MacBook Air 13", macOS 10.15