TULSA, Okla. (AP) - A red-faced boy wearing a dark blue shirt plopped down on the hill overlooking the 18th green, exhausted from the walk through the stifling heat at Southern Hills.

His mother pulled out a squirt bottle and started spraying him down.

This is the PGA Championship, Tulsa-style a four-day test of endurance that begins Thursday, when the temperature is forecast to reach 101. The same high is forecast for Friday. On Saturday, a break: It's only supposed to get to 99.

The hottest tournament ever? Maybe not.

"Singapore is probably the hottest I've been," said Retief Goosen, who won the U.S. Open at Southern Hills in 2001.

OK, so maybe Singapore's hotter. But a recent study published in Golf World magazine found that all six previous majors at Southern Hills were among the 25 hottest in history.

It figures this week could easily produce a long-lasting image a la Ken Venturi staggering to the finish with heat exhaustion during the 1964 U.S. Open at Congressional, or Colin Montgomerie wearing dark pants and shirt during his U.S. Open playoff at Oakmont, or pre-buff Phil Mickelson uncomfortably schvitzing through the sauna that became Bethpage in 2002.

"I love playing in the heat for a couple reasons," said Mickelson, the three-time major champion who is now in much better shape to handle the elements. "It loosens the muscles in your body up. You're able to swing a lot more rhythmically and the ball flies a lot straighter because you don't have the resistance."

Tiger Woods, hoping to avoid his first majorless season since 2004, says other than drinking more water and changing gloves more frequently, heat is no big deal.