What action prevents contamination when passing drinking water to a patient?

Labeling the mug with the person's name is vital in preventing contamination when passing drinking water to a patient. This practice ensures that each patient receives the correct beverage and helps maintain hygiene by reducing the risk of cross-contamination between patients. By clearly identifying who the cup belongs to, caregivers can minimize the chances of sharing or switching drinks, which can lead to accidental exposure or contamination.

Using disposable cups, while sanitary in many contexts, does not specifically address the risk of cross-exposure among patients since they could still be misidentified or switched if not labeled properly. Boiling the water kills pathogens but does not prevent contamination from handling or passing the cup. Using a filter can improve water quality but does not protect against contamination during the transfer of the drink to the patient. Thus, labeling is the most direct method to ensure patient safety regarding drink identification and hygiene.