A wearable medical device comprising: a plurality of patient interface components each configured to interface with a patient; a first patient interface component of the plurality of patient interface components, the first patient interface component comprising a first sensing electrode for receiving one or more signals from a first patient, and a first therapy electrode for delivering a first treatment to the first patient; a second patient interface component of the plurality of patient interface components, the second patient interface component comprising a second sensing electrode for receiving one or more signals from a second patient; and one or more processors in communication with the plurality of patient interface components, the one or more processors configured to detect a first condition of the first patient based at least in part on the one or more signals from the first patient, cause the first treatment to be delivered to the first patient, wherein the first treatment is based at least in part on the detected first condition of the first patient, and detect a second condition of the second patient based at least in part on the one or more signals from the second patient.