1. A heart monitoring system for a person, comprising: one or more wireless nodes forming a wireless mesh network; and a wearable appliance having: a wearable wireless transceiver adapted to communicate with the one or more wireless nodes; and a wearable bioelectric impedance (BI) sensor positioned near a heart or a brain to detect heart attack or stroke attack, respectively, the BI sensor coupled to the wearable wireless transceiver to communicate BI data over the wireless mesh network; and a wearable power source to power the wearable wireless transceiver and wearable BI sensor.