Final answer:
To assist with changing a peri-pad saturated with lochia on a postpartum unit, one should wear gloves and an apron or gown to protect against exposure to infectious materials.
Step-by-step explanation:
When working on a postpartum unit and needing to assist a patient with changing a peri-pad saturated with lochia, the appropriate protective apparel would be gloves and an apron or gown. This is because lochia can contain blood and other bodily fluids, posing a risk of exposure to infectious materials. Gloves protect the hands, while the apron or gown protects the clothing and skin from potential splashes or contact with these fluids.