Temperatures have reached new highs as heatwaves and wildfires scorched parts of the Northern Hemisphere, forcing the evacuation of 1,200 children close to a Greek seaside resort.
Health authorities have sounded alarms from North America to Europe and Asia, urging people to stay hydrated and shelter from the burning sun, in a stark reminder of the effects of global warming.
Near Athens, a forest fire flared in strong winds by the popular beach town of Loutraki where the mayor said holiday camps for youngsters had come under threat.
"We have saved 1,200 children who were in the holiday camps," said mayor Giorgos Gkionis.
Greek police arrested a man suspected of starting another of the ongoing wildfires, in Kouvaras, some 50km southeast of Athens, a fire service spokesman said.
Europe, the globe's fastest-warming continent, was bracing for its hottest-ever temperature on Italy's islands of Sicily and Sardinia, where a high of 48C is predicted, according to the European Space Agency.
The United Nations validated the European heat record of 48.8C set in Sicily in 2021.
"The extreme weather - an increasingly frequent occurrence in our warming climate - is having a major impact on human health, ecosystems, economies, agriculture, energy and water supplies," said World Meteorological Organization (WMO) Secretary-General Petteri Taalas.
"This underlines the increasing urgency of cutting greenhouse gas emissions as quickly and as deeply as possible."
With June already having been the world's hottest on record, according to the EU weather monitoring service, July might not be far behind.
China reported a new high for mid-July in the northwest of the country, where temperature reached 52.2C in the Xinjiang region's village of Sanbao, breaking the previous high of 50.6C set six years ago.
In nearby Turpan city, where ground surface temperatures sizzled at 80C in some parts, authorities have told workers and students to stay home and ordered special vehicles to spray water on major thoroughfares, the meteorological body said.
In Cyprus, where temperatures are expected to remain above 40C through Thursday, a 90-year-old man died as a result of heatstroke and three other senior citizens were hospitalised, health officials said.
In Japan, heatstroke alerts were issued in 32 out of the country's 47 prefectures, mainly in central and southwestern regions.
At least 60 people in Japan were treated for heatstroke, local media reported, including 51 who were taken to hospital in Tokyo.
Japan's highest-ever temperature was 41.1C first recorded in Kumagaya city in 2018.
'Oppressive' US heat
In western and southern states in the US, which are used to high temperatures, more than 80 million people were under advisories as a "widespread and oppressive" heatwave roasted the region.
California's Death Valley, often among the hottest places on Earth, reached a near-record 52C yesterday afternoon.
In Arizona, the state capital Phoenix recorded its 17th straight day above 43C, as temperatures hit 45C yesterday afternoon.
Southern California was fighting numerous wildfires, including one in Riverside County that has burned more than 7,500 acres (3,000 hectares) and prompted evacuation orders.
Historic highs forecast
In Europe, Italians were warned to prepare for "the most intense heatwave of the summer and also one of the most intense of all time," with the health ministry sounding a red alert for 16 cities including Rome, Bologna and Florence.
Temperatures were due to hit 42C-43C in Rome tomorrow, smashing the record of 40.5C set in August 2007.
Nevertheless, visitors thronged to tourist hot spots like the Colosseum and the Vatican.
"I'm from South Africa. We're used to this heat," said Jacob Vreunissen, 60, a civil engineer from Cape Town.
"You have to drink lots of water, obviously wear your hat and that's about it."
In Romania, temperatures were expected to reach 39C today.
Little reprieve is forecast for Spain, where meteorologists warned of "abnormally high" temperatures today, including up to 44C in the southern Andalusia region in what would be a regional record.
Along with the heat, parts of Asia have also been battered by torrential rain.
Torrential rains
Along with the heat, parts of Asia have also been battered by torrential rain.
South Korea's president vowed to "completely overhaul" the country's approach to extreme weather, after at least 40 people were killed in recent flooding and landslides during monsoon rains, which are forecast to continue through Wednesday.
In northern India, relentless monsoon rains have reportedly killed at least 90 people, following burning heat.
Major flooding and landslides are common during India's monsoons, but experts say climate change is increasing their frequency and severity.
It can be difficult to attribute a particular weather event to climate change, but many scientists insist that global warming is behind the intensification of heatwaves.
