Final answer:
When the baby is crowning, immediate preparation for on-scene delivery is necessary, as there may not be enough time to safely transport the mother to a hospital.
Step-by-step explanation:
If you respond to a call for a patient in active labor and after your physical exam you determine that the baby is crowning, you should prepare to deliver the baby on-scene. This is because when the baby is crowning, this indicates that the mother is in the second stage of labor.
The baby is very close to being born, and there may not be enough time to transport the patient to a hospital before the baby arrives. Therefore, it is crucial to ensure that you and your team are ready to perform a delivery on-site with the appropriate equipment and sanitization practices in place to minimize any risks to the mother and newborn.