SID is incorporated within a mains powered photoelectric smoke alarm (provided by Quell). Photoelectric alarms are suitable for detecting slow smouldering fires and fires with large particles of smoke. The monitored smoke detector sends an emergency smoke alert to the medical alarm, as well as sounding its own audible alarm and activating any connected smoke detectors. An alert to monitoring by the smoke alarm is handled in a similar manner to an emergency activation of the medical alarm.