France was on high alert on Monday as the peak of a punishing heatwave gripped the country, while wildfires raging in parts of southwest Europe showed no sign of abating.

Forecasters have put 15 French departments on the highest state of alert for extreme temperatures as neighboring Britain was poised to set new heat records this coming week.

The heatwave is the second to engulf parts of southwest Europe in weeks, and blazes burning in France, Greece, Portugal and Spain have destroyed thousands of hectares of land and forced thousands of residents and holidaymakers to flee.

Scientists blame climate change and predict more frequent and intense episodes of extreme weather such as heatwaves and drought.

This photo provided by the fire brigade of the Gironde region (SDIS 33) shows a wildfire near Landiras, southwestern France, Sunday July 17, 2022.

In France's Landes forest, in the southwest Aquitaine region, temperatures 'will be above 42 degrees Celsius' Monday forecaster Olivier Proust said.

And Brittany, which until recently has escaped the worst of the heat, could register temperatures as high as 40 degrees Celsius, say experts, which would be a record for the region.

In the southwestern Gironde region, firefighters over the weekend continued to fight to control forest blazes that have devoured nearly 11,000 hectares since Tuesday.

Meanwhile Spanish authorities reported around 20 wildfires still raging out of control in different parts of the country from the south to Galicia in the far northwest, where blazes have destroyed around 4,500 hectares of land.

The fires have already killed several civilians and emergency personnel since last week, most recently a fireman who died late on Sunday while battling a blaze in northwestern Spain.

A heat apocalypse'

The wildfires in France forced more than 16,000 people -- residents and tourists combined -- to decamp. Seven emergency shelters have been set up for evacuees.

France's interior ministry announced it would send an extra three firefighting planes, 200 firefighters and more trucks.

'In some southwestern areas, it will be a heat apocalypse,' meteorologist Francois Gourand told AFP.

This photo provided by the fire brigade of the Gironde region (SDIS 33) shows a wildfire near Landiras, southwestern France, Saturday July 16, 2022. Strong winds and hot, dry weather are frustrating French firefighters' efforts to contain a huge wildfire that raced across pine forests in the Bordeaux region.

The chapel of a historic hospital in the southeastern city of Lyon, Grand Hotel Dieu, offered refuge to tourists on Sunday including Jean-Marc, 51, who was visiting from Alsace.

'We came back to admire the place, but we can't leave, it's too hot outside. We say a prayer before the fire!' he quipped.

French cyclist Mikael Cherel, taking part in the Tour de France's 15th stage between Rodez and Carcassonne in southern France on Sunday, described 'very, very difficult conditions'.

'I've never known such a hot day on a bike. It really was no picnic.'

'Risk to life' in UK

In Spain, firefighters managed to stabilize a wildfire that ravaged 2,000 hectares of woods and bushes in the southern region of Andalusia, regional leader Juan Manuel Moreno said.

The blaze started on Friday in the Mijas mountain range inland from the southern coastal city of Malaga and it spurred the evacuation of about 3,000 people.

Around 2,000 people had since returned home and now that the blaze has stabilized, Moreno said the remaining evacuees may do the same.

Spanish Prime Minister Pedro Sanchez is due to visit the hard-hit eastern region of Extremadura on Monday where various fires have been raging for days.

In Portugal, almost the entire country remained on high alert for wildfires despite a slight drop in temperatures, after hitting 47C -- a record for the month of July -- on Thursday.

Only one major fire was burning on Sunday in the north.

The fires have killed two, injured around 60 and destroyed between 12,000 and 15,000 hectares of land in Portugal.

In the United Kingdom, the weather office issued a first-ever 'red' warning for extreme heat, cautioning there was a 'risk to life'.

The Met Office said temperatures in southern England could exceed 40C on Monday or Tuesday for the first time, leading some schools to say they would stay closed next week.

The mercury is set to reach 38C in parts of the Netherlands on Tuesday.