The ordinary ministers of baptism are the bishop, priest and deacon. However, in cases of necessity, especially in danger of death, anyone, even a non-baptised person, can baptise. They must have the intention to do as the Church does; they must either immerse in water three times or pour water over the head three times; and they must say: I baptise you in the name of the Father and of the Son and of the Holy Spirit. This should be reported as soon as possible to the parish priest. Where possible he will then celebrate the supplementary rites connected with baptism.
The reason for this special possibility is that the Lord told us baptism is necessary for salvation, and God desires that everyone be saved and come to eternal life with him.