Another runner, an unidentified man said to be 45 years old, also died.
One runner died, over 30 were hospitalized, and over 400 others sought medical attention.
A long-distance runner, he died of a heart attack while exercising on a treadmill, his family said.
In 1984, when afternoon temperatures reached 79 degrees, a 51-year-old runner from France collapsed 14 miles into the race and died.
The first runner died after collapsing at the finish line.
A French runner died during the 1983 race.
It is unknown if any runners have died following the event.
In last year's 68-degree heat, two runners in the marathon died of heart attacks.
The second runner died in the following race.
In 2009 two runners died towards the end of the race.