BORDEAUX, France — Firefighters in southwestern France said Friday they were working on four active hotspots as they tried to put out fires that ripped through 100,000 acres of forest, villages and farmland over the past week. Lt. Col. Eric Pitault, the spokesman for firefighters in the Gironde region, said that while the situation had “stabilized,” there are still several zones that are difficult for responders to access. He said authorities were hoping to have full control by the weekend. Tens of thousands of people near Bordeaux who were evacuated due to fire risk were allowed to return to their homes on Thursday night, as the rest of Europe continued to tackle a historic heatwave. “It’s the first somewhat optimistic day,” said Sophie Brocas, prefect of Bordeaux’s Gironde region, as she allowed the 84,000 evacuees to return home. Some 60,000 had been allowed to return to their homes on Tuesday, according to the Associated Press.