Europe braced for record-smashing heat Tuesday as withering heatwaves across the globe showed no signs of easing, and ongoing wildfires in Greece and the Canary Islands threatened homes while worsening air quality.
Across vast swathes of the planet, from California to China, authorities have warned of the health dangers of the extreme heat, urging people to drink water and shelter from the burning sun.
In a stark reminder of the effects of global warming, the UN's World Meteorological Agency (WMO) said the trend of heatwaves "shows no signs of decreasing".
"These events will continue to grow in intensity, and the world needs to prepare for more intense heatwaves," John Nairn, a senior extreme heat advisor at the WMO told reporters in Geneva.
Temperatures were unforgiving in Italy and in Spain, where three regions were put under hot weather red alerts. But as of midday, the Italian islands of Sardinia and Sicily had yet to surpass a continent-wide record of 48.8 degrees Celsius, (119.8 degrees Fahrenheit), recorded in Sicily in August 2021.
Many throughout Italy sought escape by the sea, including outside Rome, where the midday heat hit 40 degrees.
"Certainly it's better at the beach, you can at least get a little wind from the sea. It's not even possible to remain in the city, too hot," said Virginia Cesario, 30, at the Focene beach near the capital.
Back in Rome, street hawkers substituted parasols and fans for selfie sticks, as tourists struggled to find rare patches of shade and waiters sported short sleeves instead of their customary more formal attire.
Tourists still needed to eat, said Mauro Natale, 45, a waiter at a cafe near the Pantheon, but "instead of a carbonara or an amatriciana (pasta), they just want to eat salad."
Northwest of the Greek capital Athens, a vast cloud of smoke loomed over the forest of Dervenohoria, where one of several fires around the capital and beyond was still burning.
Fire spokesman Yannis Artopios called it "a difficult day", with another heatwave on the horizon for Thursday, with expected temperatures of 44C.
Still burning was a forest fire by the seaside resort of Loutraki, where the mayor said 1,200 children had been evacuated Monday from holiday camps.
The heatwaves across Europe and the globe are "not one single phenomenon but several acting at the same time," said Robert Vautard, director of France's Pierre-Simon Laplace climate institute.
"But they are all strengthened by one factor: climate change."
- 'Horrible, horrible' -
Health authorities in Italy issued red alerts for 20 cities, from Naples in the south to Venice in the north.
At Lanusei, near Sardinia's eastern coast, a children's summer camp was restricting beach visits to the early morning and forbidding sports, teacher Morgana Cucca told AFP.
In the Sardinian capital of Cagliari, pharmacist Teresa Angioni said patients were complaining of heat-related symptoms.
"They mainly buy magnesium and potassium supplements and ask us to measure their blood pressure, which is often low," Angioni said.
In drought-stricken Spain, temperatures were set to reach highs of 44C in Catalonia and the Balearic Islands.
"You can't be in the street, it's horrible, horrible, horrible, horrible, horrible," said Lidia Rodriguez, 27, in Madrid.
In the Canary Islands, some 400 firefighters battled a wildfire that has ravaged 3,500 hectares of forest and forced 4,000 residents to evacuate, with authorities warning residents to wear face masks outside due to poor air quality.
- 'Global leadership' -
In parts of Asia, record temperatures have triggered torrential rain.
Nearly 260,000 people were evacuated in southern China and Vietnam before a typhoon made landfall late Monday, bringing fierce winds and rain, but weakening to a tropical storm by Tuesday.
China reported a new mid-July high of 52.2C in the northwestern Xinjiang region's village of Sanbao, breaking the previous high of 50.6C set six years ago.
In Japan, heatstroke alerts were issued in 32 of 47 prefectures, mainly in central and southwestern regions.
The record-setting heat came as US climate envoy John Kerry met with Chinese officials in Beijing, as the world's two largest polluters revive stalled diplomacy on reducing planet-warming emissions.
Speaking Tuesday at Beijing's Great Hall of the People with China's top diplomat Wang Yi, Kerry called for "global leadership" on climate issues.
- 'Oppressive' US heat -
In the normally hot and dry western and southern US states, more than 80 million people were under advisories for a "widespread and oppressive" heatwave that sent temperatures at California's Death Valley to a near-record 52C Sunday.
In Arizona, state capital Phoenix tied its record of 18 consecutive days above 43C, and temperatures were expected to hit 47C Tuesday.
In Southern California, several wildfires have ignited in recent days, including the largest, the Rabbit Fire, between Los Angeles and Palm Springs.
As of Monday night, it was only 45 percent contained after burning nearly 8,200 acres, authorities said.