TidyMacA Mac usually runs hot because something keeps the processor busy: a browser tab, a sync or backup, Spotlight indexing after an update, a video call, or a build. Open Activity Monitor, sort by % CPU, and quit or pause what’s busy. Keep the vents clear and use the Mac on a hard, flat surface.
- Open Activity Monitor (Applications › Utilities) and choose the CPU tab.
- Sort by % CPU to see what is using the most.
- Quit or pause the busy app; in a browser, close the heaviest tabs.
- Check the Energy tab for apps with a high energy impact.
- Let one-off jobs finish: Spotlight indexing, Photos analysis and backups after an update.
- Keep the vents clear and use the Mac on a hard, flat surface.
- Restart if a process stays stuck at high CPU.
Is it actually too hot?
Macs manage their own temperature. Under heavy load they run warm and the fans (on Macs that have them) get louder; if it gets hotter still, macOS slows the processor down to protect it. Warm to the touch during a video export is normal. Hot and slow while you're doing nothing isn't.
Find what's keeping it busy
Open Activity Monitor and choose CPU. Click the % CPU column to sort. The figure is per core, so values above 100% are normal on a multi-core Mac for busy apps. The Energy tab shows which apps have used the most power recently, which is useful on a MacBook.
The usual suspects
- Browser tabs with video, maps or heavy web apps. Each tab can show up as its own process.
- mds, mds_stores, mdworker: Spotlight indexing. Common after a macOS update or when you connect a big drive. It finishes on its own.
- photoanalysisd: Photos analysing your library, often when the Mac is idle.
- backupd: a Time Machine backup in progress.
- kernel_task using a lot of CPU: this is usually macOS keeping the processor *from* doing work so it can cool down. It's a symptom of heat, not the cause.
- WindowServer: draws everything on screen; more displays and windows mean more work.
- Video calls, games, exports and builds (Xcode, Docker, compilers) are legitimately heavy.
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Cool it down without losing work
- Quit apps you're not using, or close their heavy windows and tabs.
- Pause what can wait: sync clients and backups usually have a pause option.
- Give it air: vents must not be blocked by a bed, pillow or lap blanket. Apple designs Macs for room temperatures roughly between 10 and 35 °C (50 to 95 °F); direct sun or a hot car pushes past that.
- Restart if one process stays pinned at high CPU for no reason.
Can a full disk make it worse?
When memory runs short, macOS moves data to disk (swap). On a nearly full disk there's less room for that, and everything feels slower. Check the Memory tab's Memory Pressure graph; if it's often yellow or red, quit memory-heavy apps. What swap is · Free up space
How TidyMac helps
TidyMac shows real temperature, CPU and memory in its menu bar Mac Health panel, and tells you when your Mac is running hot or an app has been busy for a long time, naming the app. Its cool-down Boost calms busy background apps instead of quitting them, so you don't lose work.