How to avoid 100% CPU load when screen-sharing through zoom
Zoom is a video conference tool that has great screen-sharing support on Linux. 
However, Zoom's screen sharing causes immense CPU load, slowing down other applications, and on laptops the CPU fan going at full speed will drive you insane.
To fix that, open Zoom's settings dialog (cog icon in the top right), and in the "General" section set the "Limit your screen share to X frames per second" option.
I suggest you set to 4 FPS. This may sound very low but is actually enough for pair programming or demoing something.
To reduce CPU load even further, consider disabling video while sharing your screen.
 Zoom's screen sharing is great because you can share one screen in a multi-monitor setup. In browser-based screen sharing, on Linux you can only share application windows or all displays at once.