coretemp0: critical temperature detected, suggest system shutdown

[John Levine]

>the problem is that the temperatures did not change. Only the message
>appeared. The idle machine is still around 50 to 60 and a loaded
>machine is still 96, all in Celsius. As I live in the tropics, these
>temperatures are perfectly normal.

I expect that the thermocouple that measures the temperature has aged
and is reporting higher temperatures.  Before assuming that, I would
check that you don't have dust clogging the vents or otherwise
impaired airflow.

Look at the man page for acpi_thermal to change the temperature
warnings.

My laptop was shutting down from overtemperature until I realized that
I had placed it next to something that was blocking the fan vent.

R's,
John