Final answer:
The safe area for capillary puncture in infants is the medial plantar surface of the heel.
Step-by-step explanation:
The safe area for capillary puncture in infants is the medial plantar surface of the heel. This area is chosen because it is rich in capillaries and relatively pain-free for the infant. The medial plantar artery supplies blood to the medial plantar surfaces of the foot, making it an ideal location for a capillary puncture.