Marita Moloney
Live reporter

We're going to pause our live coverage now, as extreme heat continues to grip many parts of the world.

Blazing sunshine, record temperatures and wildfires have prompted not just weather alerts, but also warnings from the UN's World Meteorological Organization (WMO), among others, about the implicit health risks.

The WMO says heatwaves will become more severe in the years ahead, and extreme weather patterns highlight the need for more rapid climate action.

This explainer outlines four ways in which climate change is affecting the weather, while the BBC's climate editor looks at why this summer has been so hot here.

You can also keep up to date with the latest developments on the heatwaves here.

Today's page was edited by Nathan Williams, Victoria Lindrea and myself, and written by Jasmine Andersson, Krystyna Gajda, Basillioh Rukanga, Adam Durbin, Ali Abbas Ahmadi, James Gregory, Jacqueline Howard and Nadine Yousef. Thanks for joining us.

Image source, Reuters

Across the world, millions of people are being impacted by extreme weather. If you’re just joining us, here's a quick summary of the latest:

• Red alerts, warning people of a very high risk to health due to the intense heat, remain in place for most of Italy, Spain, Greece and parts of the Balkans
• The EU is sending firefighting planes to mainland Greece as it attempts to tackle wildfires, including one that has led to the evacuation of 1,200 children from a summer camp
• The Italian island of Sardinia is expected to see a high of 46C (114.8F) today
• Spain has also faced consecutive heatwaves, and the highest-ever temperature for Catalonia has provisionally been exceeded, with 45.2C recorded at Figueres
• Crews in Switzerland are battling a wildfire close to the village of Bitsch which began on Monday afternoon and has spread "explosively"
• Elsewhere, more than 80 million people in western and southern US states are under advisories for a "widespread and oppressive" heatwave, whilr temperatures at California's Death Valley hit a near-record 52C (125.6F) Sunday
• China provisionally broke its record for all-time highest temperature on Sunday when it recorded 52.2C (126F) in its western Xinjiang region, according to the UK Met Office
• The World Meteorological Organization says extreme weather patterns highlight the need for more climate action

Azadeh Moshiri
Reporting from Kouvaras, Greece

Image source, Reuters

The sun is setting here, in Kouvaras, southeast of Athens. When the day began, I spoke to firefighters stationed here.

They’re the ones who’ve helped put out the fire and evacuate locals to safety. They confirmed Kouvaras is safe to report from, despite how decimated its hills have become. All those who were evacuated have been returning to their homes.

When I asked the firefighters about their operation in Kouvaras, one of them made a point of saying, “we are fighting fires all over Greece. Not just near Athens. We are everywhere”.

The tension in his answer was understandable. In 2021, the Greek government and emergency services were criticised by locals for not responding to the wildfires quick enough, and for focusing far more on areas around Athens.

That year Greek Prime Minister Kyriakos Mitsotakis approved €500m for wildfire relief and promised to bolster the firefighting service.

Before leaving their truck, I asked the same firefighter whether he thought there would be more blazes in Kouvaras this week. He didn’t like my question. He pointed squarely at my face and said “don’t jinx it”.

More from the UN's World Meteorological Organization, highlighting the dangers of continued hot nights.

"Repeated high night-time temperatures are particularly dangerous for human health because the body is unable to recover from sustained heat," says John Nairn, senior extreme heat advisor, speaking to reporters in Geneva.

"This leads to increased cases of heart attacks and death - that's not the only diseases that we see, but they're the notable ones."

While sweltering daytime temperatures receive the most attention, Nairn explains, high overnight temperatures are actually a greater health risk, particularly for the most vulnerable in the population.

Image source, Reuters

Sweltering temperatures are being recorded across the US, with the country's National Weather Service warning that record-breaking temperatures are being experienced across the southern belt.

The relentless heat is affecting Death Valley at all hours of the day, with the weather station in southern California recording temperatures of 48.9C (120F) at midnight, the hottest on record.

Phoenix, Arizona - one of the hottest cities on the US - has entered its 19th consecutive day of temperatures at, or above, 43C (110F) surpassing a 49-year record.

Several parts of Las Vegas, Nevada, are under an excessive heat warning, with alerts for extreme heat in the Mojave Desert in place until Saturday and temperatures projected to hit 45C on Friday (113F).

Miami, Florida, is also dealing with a grim milestone: its worst heatwave on record. On Sunday, Miami-Dade county issued its first ever excessive heat warning, prompting the city to open up 14 cooling sites.

Today, the temperature sits between 40C-43C (105 and 110F).

Countries across the world are experiencing record high temperatures.

The BBC's Chris Fawkes has the weather forecast for the days ahead, looking at how high temperatures are getting in the northern hemisphere.

Image source, Reuters

John Nairn, senior heat advisor at the World Meteorological Organization (WMO), has been speaking to the BBC about the extreme heat being seen this week.

He says he's unfortunately not surprised by the high temperatures, and what we're seeing now is on track with what global scientists have predicted for some time.

Speaking to BBC Radio 4's PM programme, Nairn explains that people need to be cautious and aware of the minimum temperatures, as well as the maximums.

"The longer that people endure high night-time temperatures is more of a problem. If you can't get relief from those very high temperatures during the day, then people won't get the recovery they need," he says.

Asked about extreme cold weather, Nairn says the trend is that cold weather will stay with us but we'll see fewer events over time. "Because the background warming is nonstop, it does slowly erode the frequency of those events," he adds.

Image source, Getty Images

Europe’s temperatures are pretty unlikely to reach the highest ever temperature of 48.8C (119.8F) previously recorded in the continent.

While the official maximums likely won't be for a few hours yet – the highest recorded so far is in Sicily, where the mercury reached 46.3C.

The highest ever temperature for Catalonia, Spain, has provisionally been exceeded, with 45.2C recorded at Figueres. The weather agency Meteocat reports that 31 stations in the region a reported new highs of above the highest of 43C.

The French weather agency Météo-France is also reporting unprecedented high temperatures in some eastern Pyrenean valleys.

Europe's highest recorded temperature of 48.8C was registered in Sicily two years ago.

The European Space Agency had last week forecast the temperatures to climb to 48°C on the islands of Sicily and Sardinia.

Natasha Booty
BBC News

Image source, AFP

Some of the hottest temperatures today were expected in Tunisia, about one-third of which is covered by the Sahara Desert.

The Sahara is one of the world’s most inhospitable regions, yet migrants frequently cross it in the hopes of reaching the Mediterranean sea, and ultimately, Europe.

Following a wave of racist violence in the Tunisian city of Sfax, some sub-Saharan Africans have fled to a militarised buffer zone bordering Libya.

Officials in Libya have also accused Tunisia of dumping hundreds of migrants over the border in the desert - with no food, water or shelter.

Both Libya and the UN say they have rescued migrants from the border.

Tunisia - which recently signed a migration pact with the EU - has not commented on Libya's allegations.

Davide Ghiglione
Reporting from Palermo

The streets of Palermo in Sicily are brimming with vitality, as tourists and locals bustle around the market and vendors sell arancini - deep-fried stuffed rice balls, a local speciality - and yell at each other from their stalls despite the extreme heat.

But Attilio Scalisi, 68, is worried.

"We are at the front-line of a climate crisis," he tells the BBC.

The southernmost Italian region of Sicily is one of the hottest in Europe. This week it is grappling with a severe heatwave which has left its residents once again bewildered by the unpredictability of the weather.

"Summers have always been warm, but this heat is abnormal. Temperatures used to rise gradually, then reach their peak in the middle of August - but now it's all completely unpredictable," says Attilio.

"We have these sudden explosions of heat that last three or four days, or a week, with extreme temperatures rising, then dropping, then rising again.

"We are not prepared for this."

With temperatures expected to soar to record highs this week, locals find themselves confronting the harsh reality of climate change and its impact on their lives and the environment.

"Even flowers don't know when to bloom anymore," says Chiara Mimì, a tour guide who organises bike trips across the island.

"Climate change is also our fault. On the one hand we need to correct our habits and try to save our planet, on the other hand we need to adapt to this new normal, urgently."

Image source, Reuters

Power shortages, triggered by the heatwave in the Gaza Strip, has prompted an uproar among residents and sparked an online campaign against the region's only electricity plant.

Temperatures have risen to over 38C (100F) in the enclave bound by the Mediterranean Sea, Israel and Egypt, where more than two million people live.

Gaza receives around 120 megawatts of power a day from Israel and its sole plant generates another 60. But local officials say the Gaza needs around 500 megawatts in summer months.

Some angry residents have taken to social media to complain about the continuing power cuts, which can last up to 12 hours a day, and have called for the plant to be run at full capacity.

They are also expressing frustration with the Hamas group who control the strip – encouraging people to raise their voice against the authorities.

"Our dreams have shrunk from [achieving] the right of return and liberating the homeland to one extra hour of electricity," local journalist Abdel-Hamid Abdel-Ati told the Reuters news agency.

Image source, Getty Images

Phoenix, Arizona - one of the hottest cities in the US - is set to reach a grim milestone today: 19 consecutive days of high temperatures at or above 43C (110F), surpassing a 49-year record.

The desert city had already been grappling with unbearable heat earlier this week - so hot that people have suffered serious burns from touching the pavement.

Doctors at a local burn centre told the Washington Post that they had 10 patients last week with contact burns , externalwhich were serious enough to require hospitalisation.

Often the victims are elderly people who fall, or homeless people sat out on the pavement.

There are also cases of people being burnt by their car seat or mailboxes, or toddlers who accidentally step barefooted onto a concrete patio.

Some are even burned by the water coming out of their garden hose.

“That first burst of water out of there, it’s practically boiling,” Kevin Foster, a doctor, told the newspaper.

Phoenix is projected to continue to get hotter this week, with a temperature of up to 46C (116F) forecast for Friday.

Sofia Bettiza
BBC News

Hospitals in Italy have been asked to activate a ‘heat code’ in emergency rooms.

The system is similar to what Italy did during the Covid pandemic: designating a separate tranche of medical staff and a specific procedure to deal with patients who arrive at a hospital with symptoms caused by the heat.

“We are seeing an increase in admissions of patients with headache, tachycardia [abnormally fast resting heart-rate], dehydration and confusion,” said Dr Tiziana Maniscalchi, director of emergency medicine at a hospital in Palermo.

“The priority is to rehydrate them quickly.”

She says several patients have died – not just because of the heatwave, but the heat was a contributing factor.

“For people who already have a fragile health, being exposed to these temperatures can have devastating consequences.”

“I am worried, because the people who will pay the price are the most vulnerable and frail.”

Marco Silva
Climate disinformation reporter

Unfounded suggestions that no heatwave is taking place in France have been spreading on Twitter.

The hashtag #SecheresseMonCul has been trending across the country, with thousands of tweets shared in the past few hours.

Some users posted videos showing rainy weather, ironically describing the heatwave as “asymptomatic”, or unnoticeable, to most. Others posted photos showing lush fields and full rivers.

This has led some to conclude that no heatwave is actually taking place, and that climate change is a hoax.

Criticising what they described as “media hysteria”, other users went as far as suggesting, without evidence, that journalists and politicians are conspiring to spread fear.

The overwhelming weight of scientific evidence has found that world temperatures are rising. As a result of that, warming, extreme weather events are becoming more frequent and more intense.

While individual weather events - such as rainy or cold days - will still continue to take place in a warming planet, they are not representative of long-term climate trends.

The EU has announced it is mobilising Canadairs - or amphibious aircraft designed for aerial firefighting - to send to mainland Greece to help battle the wildfires raging near Athens..

The aircraft are being sent from France and Italy, while firefighters from Romania are also assisting, European Commissioner for the Environment Virginijus Sinkevičius said in a tweet, external.

Image source, Reuters

Image source, European Commission

As we've been reporting, wildfires are raging in several ares of southern Europe - including mainland Greece.

The most severe fire in the country currently is in the Dervenochoria region - about 30km (18.6 miles) north-west of the capital Athens.

Smoke billowing from the area and neighbouring Attica municipality (which encompasses the metropolitan area of Athens) can be seen on satellite imagery shared by the EU.

Canadairs - or amphibious aircraft designed for aerial fire-fighting - have been sent from France and Italy, while firefighters from Romania are also assisting, according to European Commissioner for the Environment Virginijus Sinkevičius.

Local media is reporting that the towns of Panorama, Pournari, Paleochori, Agios Sotiras, Nea Zois Mandras and Neos Pontos Mandras have been evacuated.

Fires are also raging in the coastal town of Loutraki, west of Athens.

Local media is reporting that strong winds in the region are making it difficult for firefighters to extinguish the blaze.

We're going to return our attention to the extreme heat being experienced in swathes of southern Europe now, so here's a quick summary of the latest:

• Sweltering temperatures are continuing across Italy as a heatwave is expected to peak today
• Forecasts suggest 46C may be registered in Sardinia during the day
• There are warnings that the extreme heat could continue for a further ten days in Italy
• Europe's highest recorded temperature of 48.8C was registered in Sicily two years ago
• Wildfires are raging in several areas of southern Europe
• 20 Italian cities are now under a heatwave alert
• Hot weather alerts are also in place across most of Spain
• There have also been reports of power cuts in some areas of Spain as demand surges because of air conditioners

Thanks for your questionspublished at 15:18 British Summer Time 18 July 2023

15:18 BST 18 July 2023

We're going to be ending our YQA on the extreme heat and its impact now.

Thanks for joining us, we appreciate you sending in your questions to keep our experts busy!

What more can be done to mitigate heat?published at 15:11 British Summer Time 18 July 2023

15:11 BST 18 July 2023

Dr Raquel Nunes
Environmental change and public health expert

Others are wondering what governments, or society more broadly, can do mitigate health problems some face in extreme heat. Here's what the advice says:

On top of the individual actions mentioned previously, we should also consider other measures to mitigate heat-related health problems, including warning systems, improving indoor ventilation, education and information

For example, targeting high-risk people - such as the elderly, the chronically ill, children, those who are socially isolated and outdoor workers - with these mitigations.

And considering the wider determinants of health, including social, economic and environmental factors - such as income, housing quality, social networks and healthy workplaces.

Government and society, as a whole, need to do more and better to prevent the health impacts of heat - and wider support actions should also be considered

These measures should include going to cool public spaces, such as libraries and community centres; promoting checks on vulnerable individuals, and providing information via heat-health phone helplines.