Wildfires are continuing to rage in parts of France and Spain as concerns grow that the latest heatwave could exacerbate the disaster.

The fires, which began in southwestern France, in Gironde, on Wednesday last week, have already burned nearly 104,000 acres in France and around 190,000 acres in Spain. The fires have forced nearly 300,000 people to evacuate the regions.

Gironde’s prefecture has said the situation has remained stable overnight, with a total of 93 firefighters injured, according to regional broadcaster France 3 Aquitaine. “The night was calm,” the prefecture said. “the fire is still under control this morning.”

As firefighters work to bring the situation under control, there’s growing anxiety about a new heatwave expected to affect France and Spain for the rest of the week, with temperatures forecasted to rise to 33 to 35 degrees Celsius in France, according to Météo-France.

The wildfires are a rare and dangerous “pyrocumulonimbus,” a type of fire cloud that can generate its own thunderstorms, winds, and whirlwinds, making it “erratic and unmanageable,” Nicolas Braz, a firefighter Captain, told AFP on Monday.

Stefan Doerr, a professor of wildland fire science at Swansea University, told CNBC’s “Squawk Box Europe” on Monday that wildfires aren’t unusual, but that three heatwaves this summer across the region have been unprecedented.

“The overall scale of the events now is beyond the capability of dealing with it effectively,” he said.

French ‌Finance Minister Roland Lescure ‌said the crisis delivered a blow to the local economy. “It’s ​like a clap of thunder for ​an ​area ​which could ​have done without this,” he told reporters.

Georg Zachmann, a senior fellow at Bruegel specializing in energy and climate policies, told CNBC’s “Squawk Box Europe” on Tuesday that fires were “existential for the regions that have to pay for the evacuations, for the cost of firefighting, and eventually the infrastructure recovery.”

“And even at the country level, we will see it in the in the fiscal budget of the countries,” he said. “The 2025 fires in California might have cost some 40 to 60 billion in direct cost, and the indirect cost have been estimated to be some 300 billion. So it’s it’s really a big thing.”