From Brian Keogh in Tulsa
The only thing hotter than the Oklahoma weather right now is Tiger Woods' bid for that elusive 13th major.
But Ireland's "Big Two" Padraig Harrington and Darren Clarke could still have a say in the destiny of the season's final major.
The only heat on Harrington is the pressure he puts on himself to perform.
But it is different for Darren Clarke, who hopes to turn an important corner in his life following the death of his wife Heather 12 months ago next Monday.
If he fails to win here this week, Harrington can console himself with the thought that he lifted the Open exactly one month ago.
But for Clarke, Monday marks the first anniversary of Heather Clarke's passing and not even a first major victory will ease that pain.
Sweating profusely after a scorching practice session, rotund Clarke knows that he has been written off this week as a 150-1 no-hoper.
A miserable 144th in the world, Clarke said: "I’ve got a difficult date coming up again next Monday but you know it’s almost a milestone in one respect – I’ve done every birthday, every anniversary, all that sort of thing in a year’s period.
"I’ll just keep battling on and one of these days I’ll just play alright again. I’m close. I genuinely feel I am close to doing it again, I really do.
"One of these weeks I’m going to start playing properly again and it might as well be this week. But we’ll see."
If Clarke wins the US PGA, it will go down as one of the greatest comebacks in the history of golf.
A year ago he was preparing for her funeral, but this week he hopes to announce his golfing resurrection on a course where the odds are stacked heavily against him.
He hasn't had a top 10 finish since the Scottish Open 13 months ago and has missed nine cuts and withdrawn twice with injury since January.
Not only that. The 7,130-yard par-70 track takes the driver out of his hands and with temperatures set to soar over 100F every day, he looks fit to melt.
Flopping into a chair behind Southern Hills ninth green, Clarke confessed that it was hot, too hot to wear himself out by playing the back nine with Lee Westwood and Vijay Singh.
Dragging on a cigarette, he said: "The heat factor? It's massive. For everybody, from Tiger to everybody. It’s massive. You’ve got to be drinking that much.
"Someone was telling me that one per cent of water loss in your body is equivalent to 25 per cent less power with your swing.
"And it was somebody intelligent who told me. Not somebody stupid. So you’ve really got to stay hydrated. It’s your head. You don’t think straight and you make mistakes.
"Just drink, drink, drink, drink. And no time for any beers or alcohol this week."
Woods won by eight shots in Akron on Sunday and confessed that the heat factor in Tulsa means nothing more to him than more frequent glove changes and the odd drop of sweat. Concentration lapses? Woods, thought not.
Hearing that Clarke shrugged and confessed: "Is that what he said? That explains why he’s the best player in the world then. But I don't think that I am at a disadvantage with Tiger this week because of that."
The mental game is Clarke's biggest obstacle and right now and he is light years behind Woods and Harrington in that department.
This week Clarke's got Harrington's head man Dr Bob Rotella in tow but he admits that the Dubliner's major winning performance proved that he is mentally one of the strongest players in the world.
He also believes that Harrington's "If I can do it anyone can" philosophy is more modesty than anything else.
Clarke said: "Padraig will be the first to admit that when he first came out his short game kept him going and going and going but he’s worked unbelievably hard on his swing and has got to a level where he is one of the best players in the world.
"Mentally he’s as strong as anybody in the world and he proved that at Carnoustie. It was fantastic to see him doing that but other people will draw inspiration from the fact that he has won one.
"He’s still the same Padraig. I played with him last week in the first two rounds. He’s still the same. I’m sure he’s a lot more confident inside."
Woods is the 2-1 hot favourite to lift the title ahead of Ernie Els with Jim Furyk, Vijay Singh, Sergio Garcia, Justin Rose and Harrington the next best.
With the ball travelling miles due to the heat - Woods hit a four iron 240 yards in practice - the world No 1 plans to plot his way around Southern Hills.
He hasn't won a major this season and with the strength in depth of world golf, he knows that it won't be easy to avoid his first majorless season since 2004
Woods said: "Each and every year this is the deepest field we play in all year. I think that lends itself to more guys being in contention, and more guys at the top of the board, which makes for good theatre.
"Golf-wise it's been pretty good but not great. I just think the major championships are valued that highly, and I've come close. I just haven't gotten it done yet."
'Yet' is the operative word here and if Harrington is to join Woods and Nick Price and become the just the third player to win the Open and the PGA in the same season, he knows he has to be precise and patient.
Harrington said: "It is quite straightforward. You need to keep the ball below the hole. That is probably the most important requirement for the week. Obviously hit it straight, but definitely keep it below the hole.
"The greens are very fast, back to front. That tends to be the play for the week; hit fairways and hit it in the middle of the green and try and hit your putts uphill.
"At this stage I've got to believe I have more of a chance after winning the Open and I'll convince myself of that by Thursday morning.
"We'll only look back in hindsight on Sunday and say if I haven't performed, say, well, maybe there is a little bit of a letdown after winning the Open."
With seven holes that dogleg to the left and four that dogleg to the right, Southern Hills is a precision golf course that requires a lot of irons and hybrid clubs off the tee.
Clarke added: "My caddie Billy and I were trying to figure out if it is a 2-iron or a 5-wood course. We haven’t quite decided that yet so I don’t really know but there’s a lot of irons off tees.
"I’d prefer to have the driver in my hands. I didn’t prefer to have it in my hands last week but I’d definitely prefer to have a driver in my hands."