Temperatures expected to rise into the 80s apparently forced 4,300 runners to sit out the 116 th Boston Marathon, which kicked off this morning in Hopkinton.
The no-shows, some 16 percent of the 27,000 registered runners, likely took marathon organizers up on an offer to defer into next year’s race, an unprecedented gesture prompted by the weather forecast.
“We’re asking runners who haven’t run previously to think about tomorrow and maybe coming back next year,” Boston Mayor Tom Menino told runner at a pre-race pasta dinner Sunday, the AP reported. “We don’t want to have any accidents out there, or anybody overtaken by the heat.”
Runners keep cool by sweating. But heat and high humidity impede the body’s cooling process, according to Dr. Corey Slovis, chair of emergency medicine at Vanderbilt University Medical Center in Nashville, Tenn.
“In temperatures above 70 degrees, the body begins to lose its ability to cool itself. And once the temperature hits 80 degrees, people begin to suffer heat illnesses, such as heat exhaustion and heat stroke,” Slovis said.
Runners with heat exhaustion might feel faint or dizzy, and have a headache or muscle cramps. If they don’t take it easy, the condition can worsen to heat stroke, a serious heat illness marked by a 104-degree body temperature causing confusion and even the loss of consciousness.
Read more on Good Morning America.