Runners pass the halfway mark in last year's Boston Marathon in Wellesley, Massachusetts, 18 April 2011. Dominick Reuter / Reuters

BOSTON, 16 April 2012 (Reuters) – The 116th Boston Marathon kicks off on Monday with as much focus on the potentially dangerous heat facing thousands of citizen runners as on the elite athletes who will scorch the course in a little over two hours. The temperature in Boston on Monday is forecast to hit 86 F (30.5 C) by early afternoon, a record for this date and about 30 F above normal, making conditions especially trying for slower runners among the 27,000 entrants, who will be out on the 26.2-mile (42-km) course for many hours. “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 Boston Athletic Association said in a note to entrants. […] Pierre d’Hemecourt, the BAA’s co-medical director, said 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 d’Hemecourt. “If you have a cough or cold, or had recent gastro-enteritis, don’t run.” Organizers are boosting supplies of water and ice along the course, and have arranged additional ambulances and medical sweep buses. Red Cross stations will add workers along the race route, and fire departments will have spray hoses in places for runners to cool down. […]

Boston marathon warns competitors about heat