By Richard Seven

Seattle Times staff reporter

The first question usually is: Why?

The next question: Who are these people?

The next: Are they crazy?

While not so blunt and far more respectful, Seattle doctor Brian Krabak researches these overarching questions as he serves as medical director for extreme races in extreme conditions. He has tended to competitors in 150-mile races in the Gobi and Sahara deserts and Chile's Atacama Crossing, and next week will be working an Antarctica race.