With high temps expected, Boston Marathon advises inexperienced, ill: 'Don't run'

BOSTON - Runners are gathering in Hopkinton for the start of the Boston Marathon with more to worry about than the up-and-down 42.195-kilometre road to Copley Square.

Temperatures are expected to rise to 30 degrees. That can be dangerous for those who aren't accustomed to running in heat.

Race organizers have warned inexperienced marathoners to sit this one out. They've been offered a deferment into next year's race.

There's no way of knowing until after the entire field crosses the starting line how many of the 27,000 registered runners will take them up on it.

Geoffrey Mutai rode perfect temperatures last year to an unprecedented victory in two hours three minutes two seconds that was the fastest marathon ever run. He's back to defend his title, along with fellow Kenyan Carolina Kilel on the women's side.