Abstract: A system comprising: at least one sensor, comprised within a wireless wearable electronic device, the sensor configured to sense, over a given time period, information enabling determination of a Heart Rate Variability (HRV) of a wearer of the wireless wearable electronic device; and one or more processing units configured to: obtain, from the sensor, the information enabling determination of the HRV of the wearer; determine, using the information, the HRV of the wearer; calculate, utilizing the HRV, a stress score indicative of a stress level of the wearer.