Jiyai Shin struggled badly in the practice round.

THE ASSOCIATED PRESS

OAKMONT, Pa. -- Oakmont Country Club, one of the most demanding courses on tour, is tormenting the U.S. Women's Open golfers with a different kind of problem: searing temperatures.

Jiyai Shin, the South Korean golfer who was briefly ranked No. 1 in the world following Lorena Ochoa's retirement earlier this year, struggled badly as practice-round readings hit 34 degrees Celsius on the suburban Pittsburgh course Tuesday.

She didn't reply when asked by reporters if she needed intravenous fluids or any medical help, but she admittedly wasn't prepared for weather that was steamier than that in Miami Beach.

With temperatures expected to remain at the same level until Friday, Shin's worry is how she'll feel when she tees off that day at 1:03 p.m. ET. She played her practice round Tuesday morning to escape the oppressive heat, but she's scheduled to be in the middle of it for Round 2.

"I'm really surprised it's so hot and humid," said Shin, a six-time LPGA Tour winner. "It's really hot and sunny all day, so green(s) and fairways are getting firm, like concrete."

Cristie Kerr, the LPGA Championship winner by 12 shots two weeks ago, didn't bother playing another full round in the sauna-like conditions. She played only nine holes on Tuesday and plans to play nine Wednesday before the women's national championship begins Thursday.

"We teed off at 7:20 (Monday) and it took us five hours and 20 minutes to play," Kerr said. "Mentally, I felt like I was a little fried at the end. You have to learn how to manage in this kind of weather. I think for me it's more mentally challenging than physically, because the physical kind of leads to the mental."

The weather is similar to that of the 1994 U.S. Open at Oakmont, when Ernie Els won in a three-way playoff.

Some golfers carried umbrellas throughout their practice rounds to shade themselves from the sun, while some of Oakmont's historically fast-rolling greens were being watered between practice groups. The large practice green already is tinged with brown spots.

The heat affected attendance, too: There appeared to be fewer spectators on the course for Tuesday's practice rounds than Monday's. Normally, such crowds increase as the tournament draws closer.

The hazy, hot and humid conditions led the USGA to allow spectators to bring their own bottled water, although other beverages had to be purchased on the course.

"It's really hot out there," said defending champion Eun-Hee Ji, who cut 30 minutes off her pre-round practice because, as she said, not much warming up is needed.

Several golfers related tales of putts rolling off Oakmont's greens, which were running a brisk 14 on the Stimpmeter that measures such speed. That's only one below the 15 of the 2007 U.S. Open won by Angel Cabrera.

Alexis Thompson, a 15-year-old who is playing the Women's Open as her first pro event, already has been briefed on what to do: drink a lot of water.

"I've just got to stay hydrated, that's for sure," she said. "Keeping my hands dry and just eating so I don't get hungry or dehydrated. I think that's the key out here."

At least there's this: Conditions are expected to be less fierce after a cold front arrives Friday and drops temperatures back to more comfortable levels for the final two rounds.