Read-only floating point value giving the major-low alarm threshold for the heatsink temperature; a reading that falls below this number triggers a major alarm, useful for spotting an under-range condition (for example a fan spinning too slowly or a signal that has dropped out) before it becomes critical. (Note: the source MIB's DESCRIPTION text for this object was copy-pasted from the ModTemp sibling and literally says "Module Temperature" instead of referring to this Sink Temperature parameter; this reading is based on the object's own name and its distinct position in the table.)