A wearable medical system includes a support structure with one or more electrodes in an unbiased state. A monitoring device monitors, for the long term, a blood-related parameter of the person. When a value of the monitored parameter reaches a threshold, such as when the person is having an actionable episode, the one or more electrodes become mechanically biased against the person's body, for making good electrical contact. As such, the one or more electrodes of the wearable medical system can be worn loosely for the long term, without making good electrical contact. This can reduce the person's aversion to wearing the medical system.
