OK I saw from another thread that it is set by the computer so I am looking into the settings of the bios hopefully I can see the settings in there someplace.
We may be having same issue.
We'd like to change CPU temperature warning threshold that shows in /var/log/messages .
It would be nice if you could share your findings with us.
So I have seen this error a couple of times.
On all the occasions the host was not compatible with ESXi 6.5.
Make sure you test that on this link https://www.vmware.com/resources/compatibility/search.php
Since its not tested hardware the results can be inconsistent.