After updating to Mac OS Monterey 12.3.1 my MBP 2018 model is running too hot. What can I do please suggest.

Hi,

Resetting SMC could solve the issue.

How to reset the SMC of your Mac - Apple Support

If it doesn't help, try to use Notebook cooler which is available at Amazon.

I'm on a 2020 iMac 27" with an external 4K UHD Samsumg monitor.

After I updated to Monterey 12.3.1, my fan runs like crazy if I have any apps open that are reasonably intensive.

If I disconnect the monitor, no issues, no fan whirring.

This only started since the update to Monterey 12.3.1.