Harry Bullen was third in the boys’ elite race Saturday at the Bull Run Invitational, the highest placing by a competitor from the area.

The Annapolis senior had been on the demanding three-mile course before, so he knew from experience to run a controlled first mile and then attack the massive hill that runners ironically refer to as “The Dip.” The strategy worked and it earned him his highest finish ever in a season-best 16 minutes 37 seconds.

Alex Giacco of Tatnall (Del.) outpaced all 130 other competitors and breezed to victory in 16:22.

“I was just shooting for 16:45,” said Bullen, who won the Howard County Invitational this month. “To blow it out of the water like that was amazing. My coaches gave me a strategy and I played it [perfectly].”

More than 3,000 runners representing 118 schools from Maryland, the District, Pennsylvania and Delaware competed in 12 races on a day that started off feeling crisp but turned hot fast.

Tatnall wasted no time heating up. It made the 90-minute drive to Hereford and then edged Severna Park by five points for the boys’ team victory. Walter Johnson was third.

Tatnall’s girls were simply devastating. The Hornets, who have qualified for the national Nike cross-country championships in each of the last six years, went 1-2-3 in their race and beat host Hereford by almost 50 points. North Penn (Pa.) was third and River Hill was fourth.

Senior Reagan Anderson was the individual winner for the Tatnall girls, blowing away the field in a chip-timed 18:58.

Rachel Yep of Mount Hebron was the top area finisher, placing seventh in 20:43.

Georgetown Visitation’s Emily Kaplan had the early lead and, with about 250 meters left, looked as if she would finish third. But she came unraveled in the heat and wound up 12th. At one point on the home stretch, the sophomore, who is in her first cross-country season, was so disoriented that she started to run the wrong way.

Kaplan did finish under her own power in 21:08. She was immediately whisked to the medical area and treated for dehydration.

Kaplan wasn’t alone. The heat caught many runners by surprise and, combined with the stress that one of the most difficult courses in the Northeast put on their bodies, it shut them down. Paramedics began lifting runners, who were splayed out all across the finishing area, into their arms like laundry and carrying them to medical tents. At least 11 athletes were treated for dehydration.

“I’m never letting this happen again,” Kaplan said.