iPhone X screen unresponsive and "fix"

My screen today suddenly became completely unresponsive. The side buttons worked but I could not restart the phone because...the screen was unresponsive. Nor could I reboot via iTunes.

Evidently, this is fairly common.

I keep the phone in my back pocket, so it stays relatively warm.

Yet the only fix I found online (not on any Apple-related site) was this link on YouTube: fix iPhone X - touchscreen unresponsive frozen-problem solution - YouTube

Yep! "Warm your iPhone X between your both hands for 10 seconds."

It worked for me. Now, I do it repeatedly throughout the day.

But...why do I suddenly have to do this? I think this is supposed to be a super-advanced piece of technology. It sure was expensive.

I hope Apple will respond with a real fix.