Three fire crews from Clitheroe and Settle attended the blaze in Grunsagill Road, Bowland-by-Bowland at around 10:10am.
A fire brigade spokesperson said the incident involved a fire in open grassland.
"One casualty was treated at the scene and conveyed to hospital by the North West Ambulance Service.
"Firefighters used one hose reel to extinguish the fire. Crews were in attendance for approximately one hour.”
The fire was the second wildfire in grassland dealt with by Lancashire Fire and Rescue Service over the past four days.
On Friday afternoon crews were called to a blaze on land in Burnley Road, Cliviger. That incident affected an area of approximately 350 square metres.
A spokesman said: “Firefighters used two drip torches, two blowers, three beaters, and one Hagglund track vehicle to extinguish the fire. They were in attendance for approximately three and a half hours.”