Homekit Automation

My parents are 85 and still living in their home. My Dad is solid but my Mom is frail. He is trying to setup a means to get an emergency response if something should happen to him.

My Dad has the iwatch with fall detection, their home is fully automated with HomeKit, his front door has a bluetooth/wifi August smart lock on it, and the furnace is controlled with a google nest smart thermostat.

What he wants to happen is, in the event he's incapacitated, for emergency services to be alerted, all the house lights to come on, the front door to unlock, and the furnace to shut off.

Is it at all feasible to have HomeKit execute a command across platforms triggered by fall detection or through Siri?