Meaning: the temperature reading of one of the thermometers in the Chassis is more than halfway between the 'warning' and 'shutdown' temperature levels. If it continues to rise, it may eventually trigger a shutdown of the DDR. The index value of the alarm indicates the thermometer index that may be looked up in the environmentals table 'temperatures' for more information about the actual thermometer reading the high value. What to do: check the Fan status, temperatures of the environment in which the DDR is, and other factors which may increase the system temperature.