Neonatal nursing is a sub-specialty of nursing care for newborn infants up to 28 days after birth. The term neonatal comes from neo, "new", and natal, "pertaining to birth or origin". Neonatal nursing requires a high degree of skill, dedication and emotional strength as they care for newborn infants with a range of problems. These problems vary between prematurity, birth defects, infection, cardiac malformations and surgical issues. Neonatal nurses are a vital part of the neonatal care team and are required to know basic newborn resuscitation, be able to control the newborn's temperature and know how to initiate cardiopulmonary and pulse oximetry monitoring. Most neonatal nurses care for infants from the time of birth until they are discharged from the hospital. There are four different levels of nurseries where a neonatal nurse might work. The updated classification of neonatal levels by the American Academy of Pediatrics (AAP) includes a Level IV. Level I consists of caring for healthy newborns. Level I nurses are now uncommon in the United States. Healthy babies typically share a room with their mother, and both patients are usually discharged from the hospital quickly. Level II provides intermediate or special care for premature or ill newborns. At this level, infants may need special therapy provided by nursing staff, or may simply need more time before being discharged. Level III, the Neonatal intensive-care unit (NICU), treats newborns who cannot be treated in the other levels and are in need of high technology to survive, such as breathing and feeding tubes. Nurses comprise over 90 percent of the NICU staff. Level IV includes all the skills of the level III but involves the extensive care the most critically and complex newborns. This facility will have 24-hour resident neonatologists and surgeons. They are involved with intricate surgical repairs like congenital cardiac issues and acquired malformations. Neonatal care became a specialty in the United States in 1960 and in that same year, the first NICU was established in the United States.