A wearable electronic device such as a wrist watch (60) is supplied with conventional clock with two pointers (32,33). The device displays a parameter indicative of how “cool” the wearer has been over the past period as a function of time, using the time axis of one of the pointers (32,33). “Coolness” can be based on the measurement of related physiological parameters like heart-rate, body temperature, movement, skin resistance or muscle activity. “Coolness” of a person is understood as being the ability to cope with stress. Therefore, the stability of physiological parameters can be used to derive a signal for the subjective trait called “coolness”. All physiological parameters can be measured by sensors (10) in the watch (60) or in the strap (50). The invention is used as a gadget for self expression and emotional feedback.