Max Temperature Apple Mac Machines Can Withstand?

I'm wondering what's the maximum temperatures Mac machines are designed to withstand.

If I keep a few browser tabs open; say about 10 tabs on Google Chrome, and run a few other programs like - email, programming IDE, Spotify, Slack; I notice that the CPU temperature quickly shoots above 55°C.

I checked the official documentation and it says the internal CPU temperature should not exceed 89°C for extended periods of time.

I'm assuming there must be some internal mechanism to prevent CPU burnout or failure. Looking for practical examples of how hot your CPU / GPU gets and when to actually put the computer to sleep.

PS: I currently have 27" iMac Machine (2011) model. It's old one, but it still packs a lot of punch.