Mac getting hot when not in use: what is running
Why a Mac gets warm while idle or asleep, how to find the background process or wake behind it, and what is normal.
Why is my Mac hot when I am not using it?
Background work such as indexing, syncing, backups or a stuck process, or a Mac that keeps waking from sleep.
How do I find it?
For idle heat: Activity Monitor sorted by % CPU. For heat after sleep: the wake log:
pmset -g log | grep -E " Wake |DarkWake" | tail -20Mac waking on its own explains the reasons.
What is the load average telling me?
uptimeLoad averages above the number of cores mean work is queuing: Mac load average.
Common questions
Why does my MacBook get hot in my bag?
It woke from sleep, often for network activity or an accessory. pmset -g log shows why.
Is a warm idle Mac normal?
Slightly warm, yes. Hot with fans running means something is busy.