Final answer:
The priority nursing action for a postpartum patient with a slight elevation in temperature is to increase hydration by encouraging oral fluids, followed by documentation of the findings.
Step-by-step explanation:
The priority nursing action when a postpartum client has a temperature of 100.2 F (37.9 C) within 4 hours after delivering is to increase hydration by encouraging oral fluids. A slight elevation in temperature can be common post-delivery, often due to dehydration or the exertion of labor. Before considering notifying the healthcare provider (HCP), which may be necessary if the temperature rises further or other symptoms develop, it is appropriate to first address potential mild dehydration. It is also important to document the findings clearly in the patient's records. In most cases, retaking the temperature could be considered if the increase persists after hydration, to observe any patterns or changes.