Southwest Europe baked under sweltering temperatures on Friday for a fifth day, with the heat sparking devastating wildfires, forcing the evacuations of thousands and ruining holidays.
Armies of firefighters battled blazes in France, Portugal and Spain as Britain braced for "extreme heat" in coming days and even Irish forecasters predicted a taste of blistering Mediterranean-style summer temperatures.
As French President Emmanuel Macros vowed authorities would do everything to mobilise resources to fight the fallout, the Bordeaux public prosecutor indicated a "criminal" origin was its main line of inquiry for at least one fire near the southwestern city.
The furnace engulfing swathes of southwest Europe is the second in weeks, with scientists blaming climate change and predicting more frequent and intense episodes of extreme weather.
In Portugal, five regions in the centre and north -- where temperatures hit a July record 47 Celsius on Thursday before dropping back -- were on red alert again Friday as more than 2,000 firefighters tackled four major blazes.
As of late Thursday, the fires had killed one person and injured around 60. Nearly 900 people had been evacuated and several dozen homes damaged or destroyed, authorities said.
Wildfires have destroyed 30,000 hectares (75,000 acres) of land this year, the largest area since Portugal's horrific summer of 2017 when around 100 people died.
In neighbouring Spain, where temperatures were as high as 37C by seven am, a fire that broke out Thursday near the Monfrague National Park, a protected area renowned for wildlife in the Extremadura region, continued to blaze.
Spanish authorities reported close on 20 fires still raging out of control with one near Mijas in the deep south, inland from regional capital Malaga, forcing some 2,300 people to evacuate their homes.
Across the Mediterranean, authorities said one person was found dead in northern Morocco as forest fires raged.
Spanish Prime Minister Pedro Sanchez tweeted he was "closely following the evolution of active fires" posing an "extreme risk".
The mercury reached 45.4C in Spain on Thursday, shy of the all-time high of 47.4C registered in August last year.
In southwestern France, flames have destroyed some 7,700 hectares since Tuesday and forced the evacuation of 11,000 people -- including many holidaymakers who decided to abandon their vacation rather than remain in makeshift shelters set up by local authorities.
Southern France, battling temperatures around 40C on Friday, is bracing for more heat next week with 16 departments already on orange, a severe alert.
- 'Post-apocalyptic' -
One fire was raging in pine forests near France's Dune du Pilat, Europe's tallest sand dune and a magnet for tourists.
"I've never seen this before and you get the feeling that it's post-apocalyptic really," said resident Karyn on Thursday shortly before the preventative evacuation order at Cazaux village near the dune.
Fire commander Laurent Dellac spoke of "tunnels of fire" around Teste-de-Buch, in the middle of the Landes forest to Bordeaux's southwest -- although nobody was reported hurt.
"The blazes are still not under control, and unfortunately conditions are windy again," firefighter spokesman Matthieu Jomain told AFP.
Britain's meteorological agency meanwhile issued its first ever "red" warning for exceptional heat with nights exceptionally warm.
The Met Office said there was a 50-percent chance on Monday or Tuesday of temperatures topping 40C for the first time, and an 80-percent chance that the country's previous record of 38.7C set in 2019 will be exceeded.
- 'Risk to life' -
UK hospitals have warned of a surge in heat-related admissions and train operators have told passengers to expect cancellations.
The Irish meteorological office issued a weather warning for Sunday, Monday and Tuesday with "exceptionally warm weather".
A high of 32C was possible on Monday, Met Eireann said, just short of Ireland's record high 33.3C set in 1887.
Belgian authorities said they expected much higher temperatures next week, with a high of 38C in parts of the country forecast for Tuesday.
Scientists blamethe increasing regularity of heatwaves on global warming.
"Climate change is driving this heatwave, just as it is driving every heatwave now," said Friederike Otto, senior lecturer in climate science at the Grantham Institute at Imperial College London.
"Greenhouse gas emissions, from burning fossil fuels like coal, gas and oil, are making heatwaves hotter, longer-lasting and more frequent," she said.