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# thermalStateDidChangeNotification

Posts when the thermal state of the system changes.

```
class let thermalStateDidChangeNotification: NSNotification.Name
```

## Discussion

The notification object is a [`ProcessInfo`](/documentation/Foundation/ProcessInfo) instance.

To receive [`thermalStateDidChangeNotification`](/documentation/Foundation/ProcessInfo/thermalStateDidChangeNotification), you must access the [`thermalState`](/documentation/Foundation/ProcessInfo/thermalState-swift.property) prior to registering for the notification.

---

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