An automatic external defibrillator configured to deliver electrical pulses and/or shocks to a heart of a patient during a cardiac emergency includes a housing supporting an electrical connector; a defibrillator electrode delivery system supported on the housing and a pair of defibrillation electrode pads supported by the defibrillator electrode delivery system. Each of the pair of defibrillation electrode pads is pre-connected to the electrical connector of the housing. A hydrogel layer of each defibrillation electrode pad is retained by the defibrillator electrode delivery system in such a manner so as to reduce a moisture vapor transmission rate thereof.