Final answer:
In a situation where a patient is on hold and a second call is an emergency, the assistant must take care of the emergency call before returning to the first call.
Step-by-step explanation:
In a situation where a patient is on hold and a second call is an emergency, the assistant must take care of the emergency call before returning to the first call. This prioritization is important because emergencies require immediate attention to prevent potential harm or loss of life. Once the emergency is resolved, the assistant can then address the first call and provide the necessary assistance.