Updated at 1:28 p.m., EST:
Two runners who collapsed early Sunday during the Philadelphia Marathon have died.
WPVI-TV reported that two males, a 21-year-old and a 30-year-old, first collapsed along the 2200 block of the Ben Franklin parkway. At the time, officials said the runners had no vitals.
They were rushed to Hahnemann Hospital, where the young men were pronounced dead.
Professor of Exercise and Sport Science at Penn State University, Scott Kretchmar, said in October that warmer weather increases the chances that a runner will become overheated and dehydrated.
He said the ideal temperatures for runners is in the mid- to upper 40s.
Temperatures in Philadelphia have been rising through the 50s Sunday morning with comfortable humidity (dew points in the mid-40s). The city will see a high of 64 degrees this afternoon, which is warmer than usual.
"That is mild for this time of year, but not record-breaking," AccuWeather.com Senior Meteorologist Kristina Pydynowski said.
She said the average high for Nov. 20 is 54 degrees, and the record high is 76 degrees from 1985.
"Today's high is more typical of late October," she said.
Results from a U.S. Army Study, reported by Running Planet, support Kretchmar's remarks. The study found that faster performances correlated with cooler temperatures, specifically, at 51-55 degrees for men and 53-57 degrees for women.
The study also found that temperatures as low as 41 degrees have the potential to give runners an even bigger boost.
Kretchmar said it's important to follow the "20-degree" rule by dressing as if it is 20 degrees warmer than it actually is. He emphasized the importance of wearing clothes with ventilation.
Cause of death for the men is unconfirmed at this time.
Snow will swing across parts of the central and northern Plains to the Upper Midwest as November ends and December begins.
As millions head home from their Thanksgiving ventures the weather may cause trouble on the roads and at the airports from the southern Appalachians to the central Rockies on Sunday.
The reprieve from heavy rain across southern India will not last with the threat for flooding downpours set to return for the final days of November.
An active storm track across northern Europe will bring more wind and rain across Germany into the new week.
Several days of heavy rain will bring the potential for significant flooding from the southern Plains to the middle Mississippi Valley into early next week.
New England (1945)
Severe "nor'easter" in New England - winds in Boston averaged 40.5 mph over a 24-hour period. The rain changed to snow which accumulated to 16 inches in interior New England. Thirty-tree deaths were attributed to the storm.
November 1972 was one of the wettest on record for the Northeastern U.S. As of the 27th, NYC had its wettest November ever with 11.36 inches. This broke the old record of 9.97 inches. Binghamton, NY, had a monthly total of 7.11 inches -- the wettest November in the 75-year history of record keeping at Broome County Airport. Binghamton also had 19.4 inches of snow -- exactly a foot above normal.
Minneapolis, MN (1983)
With 13 inches from the latest storm - set new monthly record snow for snow with 29 inches. This record was broken during November 1991.