Mac running hot after a macOS update: why it settles
Why a Mac runs warm and busy after a macOS update, which background tasks do it, and how long it usually lasts.
Why is my Mac hot after an update?
Updates trigger background work: Spotlight rebuilding its index, Photos analysing the library again, and macOS compiling machine learning models for the Neural Engine.
Which processes do it?
mds_stores and mdworker for Spotlight, photoanalysisd and mediaanalysisd for Photos, ANECompilerService for models. ANECompilerService and mds_stores explain two of them.
How long does it last?
Usually a day or two of normal use. Leaving the Mac plugged in and awake lets it finish sooner.
Common questions
Is it normal for a Mac to get hot after an update?
Yes, for a day or two while indexing and analysis run.
How do I make it stop?
Leave it plugged in and awake; the tasks finish on their own.