On a long distance like this, I try to think about technique - both running and orienteering - from the start. To run with a relaxed body and at the same time seeing how the mapper was thinking is the perfect start.
I'm not a big fan of thinking about running while I'm orienteering. But, maybe it makes a difference if the way you're thinking is "run relaxed" rather than "keep the pace up." Of course, it also makes a difference is you're a great orienteer rather than a run-of-the-mill one.
In extreme conditions - very hot or at altitude - I've had some success when I devote a fair amount of energy to thinking about running. "Run easy, slow down, don't push." That said, I've had far more bad races than good when it is hot or the race is at altitude.
OKO posted maps from the race Nordberg wrote about - part 1 and part 2.
