System shut down incorrectly due to high temperature

[Gavin Atkinson]

Hi,

I have a 6.0RC1 system which just shut down because it apparently got too 
hot.  However, as far as I can tell it was nowhere near the ACPI critical 
temperature.  From /var/log/messages:

root: WARNING: system temperature too high, shutting down soon!
kernel: acpi_tz1: WARNING - current temperature (33.0C) exceeds safe limits
syslogd: exiting on signal 15

# sysctl hw.acpi.thermal
hw.acpi.thermal.min_runtime: 0
hw.acpi.thermal.polling_rate: 10
hw.acpi.thermal.tz0.temperature: 23.0C
hw.acpi.thermal.tz0.active: -1
hw.acpi.thermal.tz0.thermal_flags: 0
hw.acpi.thermal.tz0._PSV: -1
hw.acpi.thermal.tz0._HOT: -1
hw.acpi.thermal.tz0._CRT: 110.0C
hw.acpi.thermal.tz0._ACx: 77.0C -1 -1 -1 -1 -1 -1 -1 -1 -1
hw.acpi.thermal.tz1.temperature: 22.0C
hw.acpi.thermal.tz1.active: -1
hw.acpi.thermal.tz1.thermal_flags: 0
hw.acpi.thermal.tz1._PSV: -1
hw.acpi.thermal.tz1._HOT: -1
hw.acpi.thermal.tz1._CRT: 110.0C
hw.acpi.thermal.tz1._ACx: 77.0C -1 -1 -1 -1 -1 -1 -1 -1 -1
hw.acpi.thermal.tz2.temperature: 20.0C
hw.acpi.thermal.tz2.active: -1
hw.acpi.thermal.tz2.thermal_flags: 0
hw.acpi.thermal.tz2._PSV: -1
hw.acpi.thermal.tz2._HOT: -1
hw.acpi.thermal.tz2._CRT: 80.0C
hw.acpi.thermal.tz2._ACx: 47.0C -1 -1 -1 -1 -1 -1 -1 -1 -1

tz1 _CRT is 110 degrees C, so why did it apparently shut down at 33 
degrees?

Gavin