By Miguel Llanos, msnbc.com
Temperatures were 20 to 30 degrees above normal on Monday across the Northeast -- including the Boston area where thousands were participating in the Boston Marathon even though organizers encouraged the less-prepared runners to sit out the race until next year.
Boston is forecast to hit 86 degrees F by early afternoon -- a record for an April 16 and about 30 degrees above normal.
The Boston Athletic Association, in a note to the 27,000 entrants, 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 have spray hoses in places for runners to cool down.
Reuters quoted the Boston Athletic Association's co-medical director as saying participants should be vigilant about headaches, dizziness, confusion, fatigue, nausea or vomiting, which can be symptoms of heat exhaustion or heat stroke.
"If you have underlying medical problems, such as cardiac disease or respiratory disease, think about not running," said Pierre d'Hemecourt. "If you have a cough or cold, or had recent gastro-enteritis, don't run."
Weather.com reported that the heat is coming in with southerly winds ahead of the same system that saw twisters in the central U.S.
A few areas were expected to break their records for an April 16. New York City is forecast to reach 87 at Central Park, 26 degrees above normal, but that's still four degrees shy of tying the record there, NBCNewYork.com reported.
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