The heaviest part of the blaze was spreading through the third floor of 587 Bath St. when crews arrived around 10 p.m., authorities said.
Firefighters escorted a woman from the third floor of the building while clearing the second and first floors.
The victim was turned over to EMS and was transported to Jefferson Torresdale Hospital, authorities said.
With assistance from the Bucks County Rescue Squad, Bristol Borough Emergency Management, and mutual aid fire departments, the blaze was cleared before spreading to nearby residences.
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