Some were hot Saturday at Vienna's Life Ball, a glitzy mega-party at Vienna's City Hall staged to raise funds for fighting AIDS. And some were not.

Musicians beating steel drums with flaming batons, and fire eaters spewing tongues of flames were among those sweating at the mega-event, watched by tens of thousands of gawkers pressed against restraining barriers. Then there were the hundreds of revelers with goose bumps — those wearing little more than glitter, a few strategically placed feathers or body paint that provided little warmth on a chilly May evening.

"It's a bit brisk, but I don't mind," said a woman clad in a gauzy see-through toga leaving little to the imagination who identified herself only as Babsi from Austria's Voralberg province. "I have to wear a pants-suit or business dress on Monday."

For each under-dresser there was someone so elaborately costumed that each step appeared hazardous. Some nearly tripped on heavy hooped skirts or outrageously high stiletto heels. Others repeatedly adjusted highly piled powdered wigs that threatened to slip and block their vision. Still others who paid up to 150 euros — nearly $200 — for a scarce ticket — wore tuxedos or tails.

But there were no jeans, t-shirts or cutoffs — "style police" were on hand to make sure everyone was clad suited to the occasion.

Other excesses were in abundance. Against the backdrop of an elaborate light show, musicians seated at 20 grand pianos — one for each of the 20 years the ball has been held — pounded out a Chopin polonaise as dignitaries made their grand entrance down the gigantic magenta carpet stretching from the City Hall steps all the way across the square in front of the neo-Gothic building.

They were preceded by hundreds of costume-clad figures, their hands and heads weighed down by gigantic plastic candles in memory of AIDS victims.

"The rest of the world should be grateful to Austria," declared former U.S. President Bill Clinton, one of the celebs associated with the fight against the HIV virus who attended the event. Clinton told the crowd he would donate the check he received for his appearance to his foundation which focuses on preventing the births of children with AIDS in developing countries.

"You are saving their lives, and I want to thank you," he told the Life Ball organizers.

Other international guests included actress-model Mila Jovovich, supermodel Naomi Campbell, actor Antonio Banderas and fashion designers Angela Missoni and Eva Cavalli .

The celebrities and other guests left the non-paying crowd outside after the more than three-hour opening ceremony, moving inside the festively decorated City Hall to sip on champagne, dance to hot music and nosh at sumptuous buffets until dawn.