At the top of the hill, which is a merciful 200 yards from Newton-Wellesley Hospital, Gayle Thistle directs First-Aid Station 11, one of the most vital along the Boston Marathon course.
This is not part of the famous Heartbreak Hill further east. Rather, this is a 1-mile stretch with a 55-foot incline known to runners as "Hell's Alley," and after 20 years of working the First-Aid station there, Thistle knows to be prepared.
"I've seen hyperthermia, hypothermia, hyponatremia, heart attack, diabetic emergencies, falls, sprains, blisters, diarrhea, vomiting," she said. "I've seen it all on this hill."
As four-time champion Bill Rodgers told the Globe last week, Hell's Alley has long been disregarded. But runners who take it lightly do so at their own peril. Rodgers said he has won and lost races at Hell's Alley.
"Everyone talks about the hills, but this is where the real race starts," Rodgers said.
Here's why: After the start in Hopkinton, the course descends for almost 10 miles, then makes a steep descent for three quarters of a mile and flattens out near the Natick Town Green; then, just before Mile 16, it descends again to give inexperienced runners a false sense of ease.
"They think things are going great about there because they've been going downhill," said Thistle. "But their trouble is just beginning, especially for the 10K runners."
Just before the Route 128 overpass, where Newton borders Wellesley, runners encounter Hell's Alley, where most drop-outs occur, according to the Boston Athletic Association. Said race director and veteran marathoner Dave McGillivray, "You've gone more than 15 miles and you're starting to think about the hills, about making the firehouse turn and starting to climb. You totally ignore what's going to happen just before that."
The crosswinds are surprisingly strong at the Route 128 overpass and runners may believe they've already started the Heartbreak series of hills. Unfortunately, they must first withstand Hell's Alley.
"With the Heartbreak Hills, the rise is around 80 feet, but they go up and down with a chance for some relief," said Thistle. "In this hill, it may only be 55 feet but it's all in 1 mile." Thistle has learned to borrow wheelchairs from Newton-Wellesley Hospital in case of emergencies. Sometimes help isn't always so close.
"If they don't have room over there," she said, "they have to be taken to other hospitals by ambulance."
Yesterday, as the lead truck rolled by with its clock showing 1 hour 22 minutes, the first elite men embarked on Hell's Alley without breaking stride. The elite women have already passed, as have most wheelchair competitors.
Over the next hour, Hell's Alley began to claim victims, and some racers slowed to a walk near the top of the hill.
One runner, who chose to remain anonymous, decided to visit Thistle's station because of dizziness. "Wow, that was a rough mile," said the runner, who, on the advice of First-Aid workers, decided against continuing. "I never saw it coming. I was totally focused on Wellesley."
Just below the top of the hill, a dozen spectators from St. Louis were wearing T-shirts that read "See Bob Run! Run, Bob, Run!" They were awaiting Bob Staed, a friend running Boston for the first time.
"When we see Bob, we're going to give him a banana," said one of them. Asked if he thought Staed would be craving a banana after Hell's Alley, the friend conceded, "Probably not."
Vicky Staed has watched her husband run six marathons, including two in Chicago, where he qualified for Boston. She expected to have a word with her husband, but after sizing up Hell's Alley, she said, "I don't think he's going to want to eat or talk when he gets here. In fact, I think if we want to talk with him, we should walk down to the bottom."
Mike Smith, coach of the track and field team at New Ipswich High School in New Hampshire, brought members of his team to the top of Hell's Alley for inspiration.
"They really have to anticipate this course," said Smith. "When they reach here, this is the first place they run into where it's really hot and it's their first upgrade. The Kenyans like to open it up here. This is where you see the first runners dying out." Added Mark McFadden, a cross-country runner from Medfield, "If you've ever run, even a short cross-country course, and you see these runners halfway up the hill, your lungs and legs kind of feel what they're feeling. And it's not good."