These three sections outline the lay ministries of baptism. GICI is pragmatic in suggesting that clergy alone can’t handle large numbers of baptisms. I suppose that covers two possible contingencies: large numbers of baptisms at once (such as at the Easter Vigil) or a faith community with large numbers of infants.
15. The celebrant of baptism may be assisted by other priests and deacons and also by laypersons in those parts that pertain to them, especially if there are a large number to be baptized. Provision for this is made in various parts of the rituals for adults and for children.
We’ve touched on the situation of baptism in case of emergency, a person near death. GICI mentions this, too:
16. In imminent danger of death and especially at the moment of death, when no priest or deacon is available, any member of the faithful, indeed anyone with the right intention, may and sometimes must administer baptism. In a case of simply of danger of death the sacrament should be administered, if possible, by a member of the faithful according to one of the shorter rites provided for this situation. (RCIA 375-399, Rite of Baptism for Children 157-164) Even in this case a small community should be formed to assist at the rite or, if possible, at least one or two witnesses should be present.
Note the importance of the community presence, even during an emergency situation.
17. Since they belong to the priestly people, all laypersons, especially parents and, by reason of their work, catechists, midwives, family or social workers or nurses of the sick, as well as physicians and surgeons, should be thoroughly aware, according to their capacities, of the proper method of baptizing in case of emergency. They should be taught by parish priests (pastors), deacons, and catechists. Bishops should provide appropriate means within their diocese for such instruction.
Quick poll: How many readers know of such a catechetical effort in their parishes or dioceses? How many pastors have taught lay people how to baptize?