Toshiba Tecra R850 - Manual (Page 118)

When the processor's temperature falls within normal range, the fan will be
turned off and the processor operation returned to its standard speed.
If the processor's temperature reaches an unacceptably high level with
either setting, the computer automatically shuts down to prevent any
damage. In this instance all unsaved data in memory will be lost.
R850/R840/R830
User's Manual 3-53