Hyperthermia was a factor in the death of a Maryland woman who died Saturday after a hike along the Billy Goat Trail in the season’s warmest weather, authorities said.

U.S. Park Police said the woman, identified Monday as Rachel Parkerson, 32, of Severn, Md., had been hiking along the trail before officials responded to calls just before 2 p.m. about an “unconscious female suffering from a medical emergency.”

After first responders performed CPR, Parkerson was taken by Park Police helicopter to Suburban Hospital in Bethesda, where she was later pronounced dead, police said.

In a statement, Park Police said the cause of death was “accidental, with an attributing factor of hyperthermia,” which is an abnormally high body temperature caused by the body’s failure to deal with heat, according to the National Institutes of Health. Park Police did not release other details about the cause of death.

Bruce Goldfarb, a spokesman for the Maryland Medical Examiner’s Office, said in an email that the office does not comment on “cases under investigation.”

Heidi Beatty, of Severna Park, Md., said she invited Parkerson and her husband, Dan, to join her and her son Saturday for a hike on the trail. Beatty said she often played cards with the couple and was expecting to see them that night.

The four set out on the roughly two-mile trail that meanders along the Potomac River and C&O Canal. About a half-mile in, Beatty said, Parkerson started to become winded.

“We stopped and let her catch her breath,” Beatty said Monday. At one point, she said, Parkerson said, “I can’t catch my breath. I need a moment.” They stopped for about 15 minutes before heading onward.

Beatty said Parkerson drank four bottles of water that her husband carried. Parkerson had never hiked the Billy Goat Trail, Beatty said.

About halfway up an incline, Beatty said, Parkerson and her husband stopped again so she could catch her breath. Once they reached the top, Beatty said, Parkerson was “more verbal about her discomfort.”

“She was panting and hyperventilating, and then panting again,” Beatty said. At one point, Parkerson was “alternating between saying, ‘I can do this’ and ‘I can’t do this. I can’t go any further,’ ” she said.

Two other hikers, one of whom was a nurse, stopped to help. Someone called 911, and the three women took turns performing CPR.

Emergency personnel arrived and performed CPR, gave Parkerson an IV and lifted her into a helicopter, flying her to the hospital. Beatty said she and her son, along with Parkerson’s husband, went to the hospital and “that’s where they told us she didn’t make it.”

Parkerson was a mother of three children and worked from home as an administrative assistant for a company that sold knives, Beatty said.

On a GoFundMe page, friends said she died “suddenly and unexpectedly” and described her as a loving mother, wife, daughter, sister and friend.

“She was a vibrant soul who brought joy and laughter to anyone who met her,” the page read.

Beatty said Parkerson was always “happy and upbeat.”

The death occurred as the region recorded some of its highest temperatures in three years.

The mercury reached the upper 90s at Dulles International Airport and Reagan National Airport on Saturday, but with the humidity, some areas felt like more than 110 degrees. Parkerson’s death was the first potential heat-related fatality reported over the scorching weekend in the region.

Maryland Department of Health officials said there were four heat-related deaths in the state between July 3 and 15. In Virginia, health officials said four hyperthermia deaths occurred in the central part of the state during the recent heat wave.

Montgomery County officials said they have rescued overheated hikers from the Great Falls area almost daily in recent weeks. Park officials posted signs warning visitors to avoid hiking during the hottest hours of the day.

After days of temperatures soaring into the 90s, a cold front approached the region to start the week. Tuesday’s high was expected to reach 78 degrees, followed by temperatures in the 80s through Friday.