ewtn.com/library/Liturgy/zlitur43.htm
"Later, in No. 46 of the encyclical, the Pope reminds us of those rare cases, and under what conditions, non-Catholic Christians may be admitted to the sacraments of the Eucharist, reconciliation and anointing of the sick.
This administration is limited to “Christians who are not in full communion with the Catholic Church but who greatly desire to receive these sacraments, freely request them and manifest the faith which the Catholic Church professes with regard to these sacraments. Conversely, in specific cases and in particular circumstances, Catholics too can request these same sacraments from ministers of Churches in which these sacraments are valid.”
For these reasons the Church recognizes that “in certain circumstances, by way of exception, and under certain conditions, access to these sacraments may be permitted, or even commended, for Christians of other Churches and ecclesial Communities” (No. 130).
Apart from the case of danger of death, the Episcopal conference and the local bishop may specify other grave circumstances in which a Protestant may receive these sacraments although always respecting the conditions outlined above in the Holy Father’s encyclical: “that the person be unable to have recourse for the sacrament desired to a minister of his or her own Church or ecclesial Community, ask for the sacrament of his or her own initiative, [and] manifest Catholic faith in this sacrament and be properly disposed” (No. 131).
requires permission according to the directives of the diocesan bishop and the provisions of canon law (canon 844 § 4). "