A wearable medical device includes a water-resistant/waterproof housing configured to be continuously or nearly continuously worn by a patient and formed from a water-resistant/waterproof material, and configured to prevent ingress of water in a wet environment； a plurality of ECG sensing electrodes configured to be removably coupled to the patient and to monitor an ECG of the patient； a plurality of therapy electrodes configured to be removably coupled to the patient and to deliver at least one therapeutic pulse to the patient； and a control unit disposed within the water-resistant/waterproof housing and configured to be electrically coupled to the plurality of ECG sensing electrodes and the plurality of therapy electrodes, the control unit configured to receive the monitored ECG of the patient, and responsive to detection of a cardiac arrhythmia, provide the at least one therapeutic pulse to the patient via the at least one therapy electrode.
