Residents and holidaymakers have fled towns and villages in France as fires are whipped up by high winds and tinder-dry conditions in several countries in Europe.
More than 10,000 people have been forced to leave the south-western Gironde region in the past few days.
At least 281 deaths in the two countries were linked to the heatwave.
Several towns in western Spain have been evacuated.
The head of France's firefighters' federation has warned of the impact global warming is having on civil protection. "It's firefighters, civil security who deal with the effects on a daily basis - and these effects aren't in 2030, they're right now," said Grégory Allione.
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 emissions.
Firefighters in Spain fought to protect the town of Monsagro as fires erupted further south in the Monfragüe national park, home to rare species of birds. The main N-5 route in Cáceres just east of the park was cut off when a forest fire reached the road.
Temperatures were set to top 40C in large areas of western Spain as well as Portugal on Friday. At Pinhão in the north, 47C was recorded on Thursday, a record high for July in mainland Portugal.
The Carlos III Health Institute said on Thursday that at least 43 people had died during the first two days of the latest heatwave, on Sunday and Monday, because of the heat.
Health officials in Portugal recorded 238 deaths more than normal since 7 July which they attributed to the very hot and very dry conditions. The worst affected are the elderly, children and people with chronic diseases.
More than 30 fires were active in Portugal on Friday morning, including one in a forest at Pombal in the central region of Leiria which has lasted a week. More than 300 sq km have been torched this year, a bigger area than in all of 2021.
The EU's Copernicus emergency management service tweeted a map showing the biggest fire risks across Southern Europe and Morocco.