``Fainting? They are all fainting,'' a Red Cross officer said glumly at a relief tent set up near St. Peter's Church. Dozens of pilgrims sought aid Friday, when temperatures hit 86 degrees.
More than 1,100 people sought medical assistance in the first three days of the Roman Catholic Church's annual World Youth Day. The most serious case was a 16-year-old Chilean girl who passed out and spent seven hours at a hospital Wednesday.
Firefighters have been spraying crowds with water, opening fire hydrants and keeping public lawn sprinklers going as impromptu showers.
Weather forecasters say the biggest challenge will be Saturday and Sunday, when a projected 1.5 million people gather in the Rome suburb of Tor Vergata to attend Pope John Paul II's night vigil and Sunday Mass.
As the pilgrims walk to the large field where they will stay overnight through midday Sunday, the temperature will hover around 100 degrees Fahrenheit, made even steamier by humidity above 80 percent and a scorching southern wind.
Organizers are stocking up on water--more than 910,000 gallons of bottled water on hand so far to be distributed, with another 500,000 gallons on the way.
Nearly 900 medical personnel will be on stand-by, aided by dozens of ambulances and two helicopters.