Final answer:
Heel dermal punctures are performed on children under 1 year of age because infants' fingers are too delicate and the heel area minimizes the risk of injuring bone and reduces infection risk.
Step-by-step explanation:
Dermal punctures, such as those performed on heels for children younger than 1 year, are utilized because a child's fingers are too small and delicate for these procedures. The heel provides an area that is large enough to obtain a blood sample while minimizing the risk of hitting bone, which is closer to the surface in the fingers of infants. Additionally, as children are at a higher risk for infections due to their developing immune systems, the heel is considered a safer site for puncture as it is less frequently in contact with surfaces that may harbor pathogens compared to hands.