In northern Portugal, a pilot died when his waterbombing plane crashed in the Foz Coa area, near the Spanish border.
The Portuguese authorities say at least 238 people have died from the heat over the past week.
Fires are ravaging areas of France’s south-western Gironde region, where over 12,000 people have been evacuated.
Heatwaves have become more frequent, more intense, and last longer because of human-induced climate change. The world has already warmed by about 1.1C since the industrial era began and temperatures will keep rising unless governments around the world make steep cuts to carbon emissions.
The French weather service has forecast temperatures of up to 41 degrees in parts of the country’s south on Sunday and new heat records are predicted for Monday.
Late on Saturday the country placed 22 more regional departments mostly along its Atlantic coast on high orange alert.
One resident in south-west France described the forest fires as feeling “post-apocalyptic” – “I’ve never seen this before,” Karyn, who lives near Teste-de-Buch, told news agency AFP.
Interior Minister Gerald Darmanin said fires had so far burned 10,000 hectares (25,000 acres) of land and praised firefighters’ “remarkable courage”.
Manon Jacquart was evacuated on Wednesday and has been sleeping in a shelter.
Meanwhile in the Alps climbers are being urged to postpone their trips to Mont Blanc due to the risk of rock falls caused by “exceptional climatic conditions”.
Since Tuesday, temperatures have soared to 47C in Portugal and above 40C in Spain, leaving the countryside bone dry and fuelling the fires.
Portuguese weather forecasters say temperatures will continue hovering above 40C before dropping next week.
The Portuguese pilot who died was flying solo in a Fire Boss amphibious plane.
Portugal’s fire hotspots are in the north – east of the city of Porto. Fires have destroyed 30,000 hectares (75,000 acres) of land this year – the largest area since the summer of 2017, when Portugal suffered devastating fires in which some 100 people died.
Gemma Suarez, a Spanish farmer evacuated from Casas de Miravete, sobbed as she told Reuters news agency: “What a night. We haven’t slept all night.
“A social worker came to see me to go pick up my elderly uncle. We spent the night in Navalmoral but we didn’t sleep at all. I have never seen such a big fire.”
In southern Spain, holidaymakers on the beach in Torremolinos saw big plumes of smoke rising in the hills, where several aircraft were tackling the blaze.
Ashley Baker, a Briton who lives in Mijas, told that the fire appeared more threatening on Friday, but since then the wind had blown it away from his area.
Planes have been a dropping fire retardant substance, as helicopters shuttle to and from the coast, collecting seawater to douse the flames.
Other parts of the Mediterranean are affected too. In Italy, the government has declared a state of emergency in the desiccated Po Valley – the country’s longest river is no more than a trickle in some places.
In Greece, firefighters are tackling blazes in the Feriza area, about 50km (31 miles) south-east of Athens, and near Rethymno, on the north coast of Crete. Seven villages have been evacuated near Rethymno.
In northern Morocco, several villages had to be evacuated as fires swept through the Larache, Ouezzane, Taza and Tetouan provinces. One village was totally destroyed in the Ksar El Kebir area and at least one person died in a blaze.