Darren McCollester / Getty Images
Runners take water from volunteers during the start of the 116th running of the Boston Marathon on Monday in Hopkinton, Mass.
Temperatures were 20 to 30 degrees above normal on Monday across the Northeast -- including in the Boston area where thousands ran in the Boston Marathon even though organizers encouraged less-prepared runners to sit out the race until next year.
By the afternoon, Boston hit 87 degrees F -- a record for April 16 and about 30 degrees above normal.
Up to 4,800 of the 27,000 Boston Marathon entrants were thought to have opted out after the Boston Athletic Association warned: "We have determined that the race will occur in a 'red zone' which is considered an increased risk but acceptable for high-level elite runners. However, it is not considered safe for unfit and novice runners."
The 26.2-mile course was lined with extra water, ice, Red Cross stations, ambulances and medical buses. Fire departments even had spray hoses in places for runners to cool down.
Instead of the some 27,000 runners who registered, only 22,426 actually started the race, the Associated Press reported.
By the time the winners of the top men's and women's divisions crossed the finish line just after 12 p.m. ET it was about 74 degrees. Wesley Korir of Kenya won the men's while Sharon Cherop, also of Kenya, won the women's -- both with heat-slowed times.
"I knew it was going to be hot," Korir told reporters afterwards. "I was more concerned about my hydration than even my position, where I was going to be."
It was the hottest Boston race since 1976, when temperatures hit 96 degrees.
The Boston Athletic Association's co-medical director had earlier said runners needed to be vigilant about headaches, dizziness, confusion, fatigue, nausea or vomiting.
"If you are not highly fit or if you have any underlying medical conditions (for example-cardiac disease, pulmonary disease or any of a number of medical problems), you should NOT run this race," Pierre d'Hemecourt warned in an advisory.
Weather.com reported that the heat is coming in with winds from the south.
Temperatures at 4:15 p.m. ET
A few cities were expected to break their all-time records for April 16 -- among them Concord, N.H., Burlington, Vt., Worcester, Mass., Hartford, Conn., and Albany, N.Y.
New York City was forecast to reach 87 at Central Park, 26 degrees above normal, but still four degrees shy of tying the record there, NBCNewYork.com reported.
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