Yes, it does send out an alert if you have Pushover. This I have recently experienced. Other than that, the temperature is shown in the logs.
C-7 Hub internal temp high !? - Get Help / Devices - Hubitat
EDIT: Turns out that the high temp alert is not from HE itself, but rather from an app I installed, so you can try that: [BETA -Release Candidate] Hub Information Driver Aggregation App
