Hugh Schofield
Paris Correspondent

Two children aged two and four have been found dead in their family car in the south of France, in an accident that is being linked to the heatwave.

Emergency services were called to an address in the town of Carpentras shortly after 13:00 local time (12:00 BST).

The two children were stuck inside the car after returning from a shopping trip with their mother. The full circumstances are not yet clear.

The local state prosecutor said the precise cause of death had yet to be determined, but “it is probably linked to the heatwave.”

With an exterior heat of 35C, the inside of a car with windows shut can easily reach 15 or 20 degrees above that in half an hour, experts say.

Antonia Matthews
BBC Wales

Wales is often spared the worst of extreme UK heat, but this week's heatwave will see temperatures rise to 38C to 40C in some parts of the country, according to the Met Office.

Those highs have not been seen before, and now a first red weather warning has been issued.

The current June record in of 33.7C Wales, recorded in Machynlleth in 2000, is expected to be exceeded by several degrees.

The all-time maximum temperature record - currently 37.1C recorded in 2022, also looks set to be overtaken.

The UK Health Security Agency (UKHSA) has issued a red heat-health alert for six regions in England.

A red heat-health alert indicates that a severe heatwave could have impacts beyond health, and could potentially affect transport systems, food, water, energy supplies and businesses. It means there is a risk to life for even the healthy population.

The West Midlands, East Midlands, South East, South West, London, and East of England will be under the alert from 01:00 BST on Wednesday until 23:00 on Thursday.

The agency has also issued an amber alert for North West, North East, and Yorkshire and the Humber.

This is the only the second time an alert like this has been issued.

Dr Agostinho Sousa of the UKHSA says it is "important to look out for others, especially elderly relatives, neighbours, and those with underlying health conditions".

This is separate to the red heat alert issued by the Met Office this morning.

Gabriela Pomeroy
Live reporter

"We're having lots of cold showers," says Charlotte, 23, sitting with her friends on the steps of their performing arts college in north London.

Hallie, 22, from Texas says it's still not as hot as her home town.

"I'm avoiding the tube and carrying a fan everywhere. It would be lovely to run through some fountains. Honestly I prefer the rain!" she says.

Vanessa Clarke
Education reporter

It’s very unusual for schools to close due to hot weather in England - but the decision ultimately lies in the hands of the head teacher and school leaders.

There is no legal maximum temperature for classrooms, but the World Health Organisation recommends around 24°C as a comfortable upper limit.

School leaders will be keeping a close eye - referring to their risk assessments, checking temperatures, and watching out for pupils becoming tired more quickly, especially vulnerable pupils.

And if a head teacher makes the decision to close the school, they will need to talk to the chair of governors and their academy trust or employer first - so it’s always a very carefully considered call.

Alex Akhurst
BBC UGC/Eyewitness journalist

Image source, PA Media

Beau is a teacher at a school for special education in the south of England.

She says that the extreme heat has made work much more difficult, with young people really struggling with their additional needs.

"I cannot express how much more stressful this weather makes our job," she tells the BBC. "The children suffer immensely, staff are at their limit."

She says there is no air conditioning in the building "and yet we still need to continue with our physically demanding, emotional job".

"The poor children expected to do a full school day. They are [in] pre-verbal, autistic and ADHD classes. Awful."

The heat means that some roadways could become softer or sticky, and heavy traffic could cause rutting in places, the AA says - meaning gritters could be out on some roads to help with areas that have become tacky with the heat.

Speaking to the Press Association, AA President Edmund King says: "The main risk for drivers is not that the road suddenly ‘melts’ everywhere, but that patches can become tacky or uneven.

"That can affect braking, steering and grip, especially for motorcyclists and cyclists, and can also throw up loose material."

Drivers should slow down and avoid braking hard or steering harshly, he adds.

"In these temperatures the advice remains never to leave passengers or animals unattended in parked cars even for short periods when the interior of the car can soon get as hot as an oven," King says.

Rozina Sini
BBC UGC journalist

We've been hearing from you through the day about how you're beating the heat - and how your pets are, too.

Becki Ive's cat Inca is keeping movement to a minimum while Becki works in her cabin in Shoreham By Sea in West Sussex. They're both sheltering next to the fan, which is running at full blast.

Image source, Supplied/Becky Ives

And Julie O'Hanlan's cat Riley has also opted for the fan method - they're both in the garden shed while they try to cool down.

Image source, Supplied/Julie O'Hanlon

Image source, PA Media

It's just gone lunchtime, but it has already been a warm start to the day and temperatures are only expected to rise as the week goes on. Let's bring you up to speed:

• Temperatures are forecast to increase significantly in the next few days, with the potential for 38 or 39C by mid week
• The Met Office has issued a rare red warning set to begin 09:00 BST on Wednesday to 21:00 Thursday for parts of England and Wales. The warning indicates a high likelihood of risk to life and people are being advised to avoid travelling where possible
• Critical national infrastructure could also be affected, with some trains already delayed or cancelled due to the hot weather. Schools in England's west have also closed early
• With temperatures soaring, we've put together a handy list of tips to keep yourself and your pets cool during the hot weather

• As BBC Weather's Helen Willetts explains, the heat is building due to a combination of factors and is not just limited to the UK

• In France, 845 schools have closed due to the warm weather, while in Spain's Basque region companies are being asked to adapt timetables for workers

You can get in touch in the following ways:    

• Upload your pictures and video    

• Email: yourvoice@bbc.co.uk, external, external 

 Please read our terms & conditions and privacy policy    

 In some cases a selection of your comments and questions will be published, displaying your name and location as you provide it unless you state otherwise. Your contact details will never be published. 

Jonah Fisher
Environment correspondent

Image source, Reuters

With temperatures in parts of France tipped to reach 40C this week, and up to 44C in Spain, communities with more experience dealing with heat than the UK are still bracing for a struggle.

On top of school closures, several towns in France have cancelled the annual music festival - Fête de la Musique - and the government has banned drinking alcohol in public places in areas that are under red alert.

Both France and Belgium have announced cuts to their rail services to reduce the risk of breakdowns blocking the tracks.

And in Madrid, authorities cancelled public transmission of the World Cup match against Saudi Arabia on Sunday.

Guy Hedgecoe
BBC News in Madrid

Image source, EPA

The temperature is expected to rise up to 40C today in parts of the Basque Country, which is unusual for the northern region - much of which is on a red weather alert.

The Basque regional government has brought forward its plan to manage high temperatures, which includes asking companies to adapt timetables for workers, increasing their breaks and guaranteeing access to water.

Yesterday, 25 people received medical treatment for heat-related issues in the Basque Country.

The north-eastern region of Aragón is among several expected to see temperatures in the low 40s.

In the region’s capital, Zaragoza, authorities have announced a discount on the price of entry to municipal swimming pools.

The city has also made available around 60 "heat refuges", which are air-conditioned public buildings, such as libraries, churches and civic centres, where people are encouraged to spend time during the hottest part of the day.

Jessica Parker
BBC News in Switzerland

It is baking on the shores of Switzerland's Lake Lucerne, where people are taking a dip to escape the heat.

This week temperatures are set to peak here at about 33C. Elsewhere in Switzerland, temperatures are set to get even hotter - including in the southwestern city of Geneva and northern city of Basel.

Switzerland's Federal Office for Meteorology and Climatology is urging people to drink plenty of water, seek shade and keep in touch with those who may be particularly at risk in their neighbourhood.

Hugh Schofield
Paris correspondent

Image source, Reuters

The hot weather the UK is experiencing this week is spreading from continental Europe where an extremely intense hot spell has developed.

In France, 845 junior and middle schools have closed because of the heat and a further 1800 have reorganised their teaching hours. That is about 5% of the total in the country.

But many more schools have told parents informally that it would be better not to bring their children, especially in the afternoon when temperatures will soar into the late 30s or higher.

Me personally, I have two children in junior school who will leave at lunch.

The school buildings will be simply intolerable later – despite air-conditioning units which parents have clubbed together to buy.

We are organising among ourselves to share childcare over the coming days because we assume the heatwave will last all week.

Great Western Railway says some trains are delayed or cancelled due to the hot weather.

Stations in the Thames Valley are affected, and some trains between Reading and London Paddington will be cancelled.

The train operator says "track temperatures are forecast to reach levels requiring speed restrictions. Extreme heat can cause rails to expand and buckle, so when temperatures reach certain thresholds, trains must run more slowly to keep services safe."

National Rail says there is disruption on the routes from Coryton and Penarth in south Wales, and between Pontypridd and Cardiff Bay, and people can use their tickets on the bus routes instead.

Vanessa Clarke
Education reporter

The government doesn’t normally advise schools to close – it says most of the time it can be managed safely and keeping children in school is important.

But it does expect schools to adapt to keep children safe and comfortable.

Some parents, like me, will already have had a message from their schools saying uniform rules are being relaxed, PE kits are allowed and sunscreen and sun hats are needed.

Head teachers in older school buildings, which are sometimes harder to keep cool, will have been up early opening up doors and windows to keep air moving.

Advice from the UK Health Security Agency says schools may have to close their windows later in the day if it becomes hotter outside than inside, and fans shouldn’t be used if temperatures go above 35°C.

Lessons may be moved to cooler areas of the school and hot meals may be switched for cooler options.

And schools could even look at changing start and finish times to avoid the worst of the heat – so things could look a little different this week.

Bea Swallow
BBC News, West of England

A number of schools across the West region have confirmed they will close early, citing concerns over staff and pupils spending prolonged periods inside stuffy classrooms.

In Wiltshire, Kingdown School, Clarendon Academy, Pewsey Vale School and Dilton Marsh Primary are among those who say lessons will finish at 12:30 BST.

Kingsholm Primary in Gloucester will close its doors at 13:30 BST every day until Thursday, and it has advised pupils they are welcome to wear their PE kits to class.

Justin Rowlatt
Climate editor

We tend to experience heatwaves as: a sweaty commute, a sleepless night, a warning to stay indoors. But the bigger story is even more unsettling.

Human civilisation has developed during roughly 12,000 years of unusual climate stability - a narrow band of conditions in which farming, trade, cities and all of modern life became possible.

Now, over the course of a few decades, we are pushing that system into new territory.

One broken temperature record does not prove climate change. But records falling repeatedly, across continents and seasons, show the dice are being loaded towards extremes.

That is why this heat matters.

Image source, Met Office

A red warning is the most severe level of alert which indicates dangerous weather is expected with a high likelihood of risk to life.

It could also lead to failures of critical national infrastructure, such as power outages or roads and rail lines being closed.

In situations where a red warning is issued, the Met Office advises people to avoid travelling where possible and to follow the advice of the emergency services and local authorities.

The first ever red heat warning was issued in July 2022, although the extreme heat warning system was only introduced in 2021.

Simon King
Lead weather presenter, BBC Weather

The rare red extreme heat warning issued by the Met Office covers parts of southern England, as well as the Midlands and southern Wales.

It will come into effect at 09:00 BST on Wednesday until until 21:00 BST on Thursday.

Red warnings indicate that dangerous weather is expected with a high likelihood of risk to life.

The Met Office is also warning of substantial disruption to travel, energy supplies and possibly widespread damage to property and infrastructure.