There was a bit of cross-cultural learning at the Smithsonian Folklife Festival yesterday that didn't involve lectures, demonstrations or exhibitions at the 33rd annual celebration on the National Mall. The instructor was Mother Nature.

Just ask the man called "Big Chief," a native of South Africa, who learned the real meaning of one of the most dreaded words in every Washingtonian's vocabulary: humidity.

In his traditional dress of antelope skins and goat hair, Hlangahani Hamilton Mayimele collapsed in the shade after dancing the "Xincanyi-canyi" for tourists, dumped a cup of cold water on his head and reached for the nearest strawberry smoothie.

"Usually, I don't feel the heat," said Mayimele, who is not really a chief. "At home, you go in the shade and it is better. There is no place to hide from it here."

It reached 92 degrees at Reagan National Airport yesterday, with the pain of that heat exacerbated by the high humidity, which made it feel more like 103 degrees.

And there's no relief in sight, according to Dewey Walston, a meteorologist at the National Weather Service. Today is expected to be the hottest Independence Day in many years, with the combination of heat and humidity likely to make it feel between 105 and 110 degrees.

The culprit for the hot, hazy holiday weekend is an area of high pressure parked off the coast of the Carolinas, pulling warm, moist air up from the Gulf of Mexico and over Washington. Meteorologists don't expect it to pass until Tuesday, if then.

"Stay at home and watch the fireworks on TV," Walston said. "It's going to be horrible."

First aid workers reported that "thousands" of people stopped by their tent to complain about the heat and to get free water at the festival. Three people suffering from symptoms of heatstroke were transported to George Washington University Hospital, where they were treated and released.

Many others tried to make the best of the day as they strolled around a festival that focused on South Africa, New Hampshire and Romania. Festival volunteer Adrian Carpusor, for instance, would not take off his "Romanian Pride Hat," even though its black felt was making him woozy.

Decorated with elaborate beading around the crown and a peacock feather on its right side, the hat made Carpusor, 28, a Romanian national who just graduated from the University of California at Los Angeles, feel part of the celebration.

"My head is spinning," he said. "It gets very hot in Romania but never this humid."

Festival-goers Lisa and Adriana Niedenfuhr stopped Carpusor just to comment on his headgear--and to sympathize.

"It must be terribly hot, but isn't it the neatest, neatest thing?" Lisa Niedenfuhr said to her daughter Adriana, 9. "Please don't take it off."

Niedenfuhr, an occupational therapist from the Boston area, said she brought Adriana to the festival to learn more about Romania, her homeland. Niedenfuhr adopted Adriana, who was born in a Romanian orphanage. Adriana doesn't remember much about home, Niedenfuhr said.

"Nothing would keep us away from this festival," Niedenfuhr said. "We came down to see this because there is so little about Romania in America. We can't even find good children's books."

The place reputed to be the coolest spot on the Mall was the traditional Swazi hut in the South African exhibit. Built mainly of bamboo and grasses, the hut keeps its inhabitants cool with thick but permeable walls that allow heat to escape.

Monica Zwane, who designed and built most of the house, explained the hut's engineering through an interpreter, but she had to stop often to cool herself, the oppressive heat taking its toll.

By its conclusion today, organizers said they expect about a million people to have visited the festival grounds, which stretch along the Mall from Seventh to 14th Street. Oddly, it was the folks from New Hampshire, carving logs and demonstrating how covered bridges are made, who seemed to be having the least problems with the heat.

"It's the good old work ethic of New Hampshire, just doing the job," opined Patryc Wiggins, 45, a presenter with a group demonstrating New Hampshire's "precision machine" industry. She quickly added, "We were forewarned, and luckily I'm under a tree."

CAPTION: Monica Zwane, of South Africa, designed and built the traditional Swazi hut for the South African exhibit at the Smithsonian Folklife Festival on the National Mall.

CAPTION: Sam, a Percheron horse, tries to cool off with the help of a fan in the livestock barn at the festival, which ends today.

CAPTION: Tram Tran, 8, left, and her sister Ha Tran, 5, seek heat relief in the fountains near the Washington Monument.