A protective device configured in accordance with a particular embodiment includes a cover including a first region that extends over a vulnerable site on a patient and a second region that extends over an area on the patient peripheral to the vulnerable site. The first region of the cover is at least generally impermeable to liquid water. The device further includes an adhesive film and a liquid-absorbing element. The adhesive film is configured to form an adhesive bond between the second region of the cover and the patient. The bond has an inner edge portion positioned toward the vulnerable site and an outer edge portion positioned away from the vulnerable site. The liquid-absorbing element is configured to absorb liquid contamination at the outer edge portion of the bond and/or liquid contamination approaching the outer edge portion of the bond when the cover is operably positioned on the patient.