About 200 firefighters are battling a wildfire that has ravaged about 550 hectares (1360 acres) of pine forest near a resort popular with surfers on France's Atlantic coast.
Water is being dumped from four planes in an effort to control the blaze, near Lacanau, about 25km (16 miles) west of Bordeaux.
The task is being hampered by high winds and temperatures of up to 40C.
Droughts and heat have fanned wildfires across southern Europe this year.
On Friday, firefighters said the blaze had stopped spreading but the danger was not over.
"The fire's less virulent now but the wind and soaring heat are not helping," Jerome Mesure, a fire brigade captain, told the Reuters news agency.
The mayor of Lacanau, Jean-Michel David, said the likely cause was a cigarette thrown from a car, as the fire had started near a main road.