Fix macOS Tahoe 26 Overheating on MacBook (M1--M4 & Intel)

Some users say their Macs have been running so hot after updating to macOS Tahoe 26—even at idle or with light tasks. Reports span M1, M2, M3, M4 Apple silicon and Intel machines. Common threads include high WindowServer/Spotlight activity, external display scaling, and certain apps (Mail, Teams/Intune, VS Code, design apps). A number of users say rolling back to macOS 15.7 (Sequoia) immediately returns temps to normal.

You should know that many people will run into this issue after a major upgrade like macOS Tahoe. And there are ways to prevent overheating.

The issue:

CPU/GPU sitting ~20 °C higher on Tahoe vs Sequoia; CPU/GPU ~75–80 °C sustained on affected machines.
Fans audible constantly (or kicking in every hour for a few minutes) even with light usage; "hot even in sleep."
Spinning beachballs and sluggish UI; beachballs during typical workflows (Safari, Pages, Keynote, Mail).
WindowServer using 20–40% CPU and 35–50% GPU; coreSpotlightd/Spotlight consuming large memory/CPU.
Heat worse with multiple monitors, especially when using scaled (non-native) resolutions.
Some apps implicated per user reports: Apple Mail (constant uploading/archiving loop), Microsoft Teams/Intune MDM, Visual Studio Code, Adobe/Affinity apps.

Basic troubleshooting steps

Activity Monitor > CPU tab > sort by % CPU. Identify top offenders (WindowServer, coreSpotlightd, mds, Mail, Teams/Intune, XProtectService, fileproviderd, KernelManagerd, VS Code, browser processes).
Activity Monitor > Memory tab. If coreSpotlightd/Spotlight is using GBs of memory, you likely have an indexing problem.
Reboot once. Some users saw a temporary return to normal that regressed the next day—helps confirm "recurring" triggers.

Steps to fix macOS Tahoe 26 Overheating issue:

1) Reset Spotlight/Core Spotlight indexes (one-time clean rebuild)

Open Terminal and execute these commands:

Turn off indexing everywhere:

sudo mdutil -a -i off

Erase all Spotlight indexes:

sudo mdutil -Ea

Turn indexing back on:

sudo mdutil -a -i on

Clear per-user Core Spotlight metadata:

rm -rf ~/Library/Metadata/CoreSpotlight/*

Restart the Core Spotlight daemon:

killall -9 corespotlightd

Reboot to finish cleanly:

sudo shutdown -r now

2) Check external displays and scaling

If you use 4K monitors at a scaled 2560×1440, macOS often renders at a larger buffer and downsamples—raising GPU load.

Try switching to the panel’s native 3840×2160 in System Settings > Displays for each monitor.

3) Safe Mode test

Boot in Safe Mode to disable third-party extensions/agents temporarily. If temps normalize, something in user space is likely contributing. Sometimes just using Safe Mode fixes things.

4) Trim Login Items & background agents

Settings > General > Login Items: disable anything non-essential. Quit/disable helper apps that continually scan or sync.

5) Browser & extensions

Heavy extensions (e.g., grammar checkers) in education/work LMS sites were mentioned. Limit extensions on heavy pages and see if temps improve. What to do:

Disable or limit extensions like Grammarly (I have Grammarly and I know that it uses a lot of CPU sometimes) or ad blockers to only necessary sites.
Close unused tabs and windows.
Turn off auto-play videos or animations.
If using Chrome, try Safari or disable "hardware acceleration."

6) Give indexing "day-one" time—but verify

It’s normal for indexing to churn after a major upgrade. If temps don’t settle after a day or two, use the reset in Fix #1 instead of waiting indefinitely.

7) Specific apps causing heat

Several users traced overheating to certain apps misbehaving on macOS Tahoe:

Apple Mail: Some say Mail constantly uploads or reindexes messages, keeping CPU high.
Microsoft Teams / Intune MDM: Reported to spike temps even when idle; quitting these temporarily cooled Macs.
Visual Studio Code, Adobe, Affinity apps: Can drive GPU and WindowServer usage abnormally high.

What to do: Quit these apps one by one and watch Activity Monitor. If temps drop, reinstall or update the app, or wait for a patch from the developer.