Final answer:
To determine if rescue breathing for an infant is effective, you should check the heart rate and respiration. A strong and steady heart rate, as well as regular breathing, indicate that the rescue breathing is effective.
Step-by-step explanation:
To tell if the rescue breathing for an infant is effective, you would need to assess several criteria. One important factor is the heart rate of the infant. A strong and steady heart rate indicates that the rescue breathing is effective. Additionally, you should observe the respiration of the infant. If the infant is breathing on their own or with assistance, it suggests that the rescue breathing is working.