The 115th Boston Marathon kicked off in Hopkinton, MA at 9:30 for the elite women and 10:00 for the open men's division on a brisk Patriot's Day. The temperature at the start was a chilly 46 degrees F (40 degrees with windchill), with a beneficial tailwind of about 20 mph, with gusts of up to 30 mph. About an hour into the race the temperature had warmed to mid 50s
An hour into the women's race, New Zealand runner Kim Smith had about about a minute lead over the pack. American Ryan Hall led the men's pack with a two-second lead. The half-marathon time for the men's race was a blistering 1:01, on track to beat the course record.
26.2 miles from the start line, 1,400 medical volunteers were rushing around the prepare for the rush of runners. Veteran volunteer John Andersen, a middle school science teacher from Holliston, MA, has worked the microphone overseeing the medical tent for the past decade. His job is to direct the runners as they enter the medical tent, as well as direct equipment from one section to another. There are over 20 first aid stations along the route for minor health issues, as well as "sweeper" buses located along the route to bring runners to the hospital or to more well-equiped first aid tents.
Andersen said that the medical tent at the finish line treats an average of 500-600 runners each year. Most common injuries include exhaustion, shock, muscle cramps, and imbalances of sodium levels. The medical tent also uses "Bair Huggers" which are inflatable blankets that surround the runners with a cushion of warm air in order to raise the athlete's body temperature.
The rush at the medical thent usually comes about three hours after the first wave of runners. The medical tent is busiest from 12:30 to 1:30 but continues to treat a steady stream of runners until around 4:00 PM.