Xbox one x runs warmer when its off.

Heat when it’s off? Erm.. no.. mine is just cold when it’s off. It only gets warm when it’s under real load, like when playing Assassin’s Creed. In general I’d say the original Xbox One is much warmer when touching the case.

Some games make it run warmer. MKX for example. It's normal. My cable box is always hot and I never turn it off.

I have watched the video, and I'd say that this is normal behavior.

You see, when you are on the main Home Screen, the console doesn't have much to do, and can run very quiet, as there is not much computing going on that produces heat.

However, when you start a Xbox One X enhanced game, the graphics hardware and processing power are running at peak performance, and generate much more heat than running a "normal" Xbox One game, or simply the Home Screen.

The console has an automated fan control, that can dynamically speed the fan up, when the console gets warmer. Be it because of the higher processing power for Xbox One X enhanced games, or because of the summertime, and maybe higher temperatures in your
home.

As far as the video goes, the console sounds healthy, and there is nothing you need to worry about.

Buy within your price range. I have had a Xbox one now have a Xbox one X. The One X is obviously better but if you live in warmer countries i would definitely recommend a USB cooling fan to stop it overheating as there is no longer a power converter external
to the Xbox.

Why would you need a cooling fan? You Xbox One should be running very cool anyway.

The power brick probably gets warmer than the console.