LOUISVILLE, Ky. - Somewhere along the way, the PGA Championship became the Equator Invitational.
Sauna-like humidity and temperatures in the 90s have transformed the 150-player field into a pack of survivalists at Valhalla Golf Club. Maintenance workers spritz the greens with water in order to keep them alive, but so far no one has figured out how the players will make it to Sunday.
''No need to warm up,'' Colin Montgomerie cracked Wednesday while sipping some cold water. ''It will take somebody very tough - mentally as well as physically - to win this.''
Of all people, Montgomerie might just fit that description. Long ridiculed by critics as overweight and out of shape, the Scot has dropped 20 pounds since the British Open by cutting out late-night snacks and working out every day with a personal trainer.
Even those who are physical specimens are laboring in the oppressive heat.
''A difficult obstacle this week is the heat and the humidity,'' said South Africa's Ernie Els, ranked No. 2 in the world.
''I never sweated as much in my whole life as I have been sweating these couple of days,'' said Sergio Garcia, runner-up to Tiger Woods in last year's PGA at Medinah.
At one point, Els actually said that it wasn't the heat, but the humidity.
''The humidity kind of tears you apart after 15 holes,'' said Els, who started his second practice round at 7:30 a.m. ''We teed off this morning and after the first hole we were drenched. I think a lot of players are going to struggle a bit with the heat and humidity.''
As if the conditions weren't enough, everyone will be chasing Woods. After winning the U.S. Open by 15 shots and the British Open by eight, the world's top-ranked player is seeking his third Grand Slam victory in a row and fourth in the last five. No one has won two straight PGA Championships since Denny Shute in 1936 and 1937.
Despite an incredible 12 months in which he has won 11 of 20 events and stockpiled more than $9 million in tournament money, Woods is driven by history, and still isn't satisfied.
''I did savor the moment of winning the British Open,'' he said. ''But I also understood and realized in the back of my mind that there is always one more ahead of you. Yeah, go ahead and enjoy this one because you've earned it. But, then again, don't lose sight of the fact that the year is not over yet.''
Woods took some time off after winning at St. Andrew's, then finished 11th last week at the Buick Open. He worked this week with his swing guru, Butch Harmon, and pronounced himself right on schedule to defend his title.
''This is going to be a long week,'' Woods said. ''The golf course is set up very difficult and this week is especially difficult because of the weather. Obviously, it's going to be sapping a lot of energy.''
But Woods even considers playing in a steambath as his own unique advantage.
''Luckily, I think it's cooler here than it is at home for me in Orlando,'' he said with a grin.
Montgomerie can only shake his head as he looks at what Woods has done and how he has done it.
''Any golf tournament plays into Tiger's hands right now,'' Montgomerie said.
The field in the 82nd PGA Championship includes 91 of the top 100 players in the world rankings. The winner collects $900,000 and a 10-year exemption. With the heat wave expected to continue through the weekend, whoever wins will have earned it.
''The toughest holes are near the end when our shirts may weigh more than we do,'' Nick Faldo said.