By the time the mass got underway, rain was falling on those gathered in the field. Unlike the electrical storm in Miami Friday, however, it did not disrupt the service. But by then the sun had taken its toll, with hundreds of persons treated for heat-related problems and a few dozen suffering from heart conditions carried by ambulance or medical helicopters to local hospitals for treatment.

Outside the Superdome, vendors offered those filing inside a chance to cool down with frozen ''popesickles.''

Louella Givens, a fourth grade teacher from New Orleans, bought one for her five-year old son, Llewellyn. Her views on the Pope seemed to reflect those of many American Catholics.

''I think some of the things he says in terms of family life are unrealistic,'' she said. ''But that doesn't take away from my belief in this church or my intentions to stay in the church, although he doesn't recognize our right to disagee.

''I guess,'' she continued, ''It's like any other love affair: there will be disagreements but that brings change, and for the church to be effective there has to be change. It can't stay in the 10th century.''

By coincidence, the Pope's visit to New Orleans came as 4,500 delegates to a convention of the National Association of Social Workers was concluding. ''Issues that the Pope has forced on the church such as the role of women, abortion, family planning and homosexuality are issues that concern social workers who take a more practical course to addressing social ills,'' said Octgavio Roco, media coordinator for the national convention.

Therefore, he said, most of the delegates were not overly enthused by the papal visit.

The day began for the Pope at St. Louis Cathedral on Jackson Square, where tourists gravitate to sit in outdoor cafes, drink cafe au lait and munch croissants and admire the picturesque 19th Century buildings enclosing the square. The cathedral is said to be the oldest in the continental United States, built in 1794 when Louisiana was a French terroritory.