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Check if Your Mac Is Throttling Due to Heat (pmset -g therm)

Read the live thermal pressure level from the command line to see whether a hot Mac is being slowed down by macOS.

macOShardwarepmsetPower & SleepDiagnosticsLow risk
Run pmset -g therm to print the current CPU thermal pressure level, e.g. Nominal or Heavy.

01Command

Command
$ pmset -g therm

02What it does

macOS constantly grades how much heat headroom the machine has, from Nominal through Moderate to Heavy and Trapped. When the pressure rises, the system quietly reduces CPU and GPU clocks long before any app crashes, which shows up as sluggishness. pmset -g therm prints that grade plus a CPU_Speed_Limit percentage — anything under 100 means the processor is currently capped.

03Risk

RiskLow risk
!Warning: The reading is a snapshot; run it a few times while the slowdown happens, or combine it with Activity Monitor's Energy tab to spot the culprit.

04Undo

✓No undo needed — this command does not change persistent state.

05Sources

  • pmset - Power Management Settings
    SS64 · technical · 2026-09-17
    Evidence: Lists 'therm' — show thermal pressure — among the pmset query options for the current thermal condition.
  • pmset(1) man page
    manpagez.com · technical · 2026-09-17
    Evidence: Documents 'pmset -g therm' which shows the current thermal pressure level reported by the system.

Last verified: 2026-09-19 · Category: System & Settings

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