Why Zoom heats up your Mac
- Encoding your camera into a video stream, continuously.
- Decoding other people's video, more of it in gallery view with many cameras on.
- Effects: virtual backgrounds, blur, filters and appearance touch-ups analyse every frame.
- Screen sharing, which captures and encodes your screen as well.
- External displays and high resolutions, which add work for the whole system.
Settings that make calls lighter
- Turn off virtual backgrounds and filters. In Zoom's Settings, open Background & effects and choose None. This is usually the biggest saving.
- Turn off HD video in Zoom's Settings › Video if you don't need it.
- Turn off "Touch up my appearance" and low-light adjustment in the same Video settings.
- Use speaker view in large meetings instead of gallery view, so fewer videos are decoded at once.
- Close heavy apps and tabs during calls, especially other video apps and browser tabs with video.
- Keep Zoom updated, since performance improvements ship regularly.
It's still hot. Is something wrong?
Probably not. A long call with camera and screen sharing is sustained heavy work. Give your Mac a hard surface and clear vents, and check Activity Monitor afterwards: once the call ends, CPU should drop back within a minute. If it doesn't, quit Zoom fully from its menu bar icon and reopen it.