welcome to bbc news, broadcasting to viewers in north america and around the globe. my name is mike embley. our top stories: the big freeze hits parts of the us. arctic conditions are sending temperatures down below —30 celsius. the european union insists it won't renegotiate britain's brexit deal, despite the vote in parliament seeking changes to the so—called irish border backstop. more street protests in venezuela, as president maduro refuses new elections but says he will talk to the opposition. and millions of migrants are making their way in record numbers from north america to mexico. millions in the american midwest are experiencing a blast of arctic air so ferocious they are being warned they risk frostbite if they stay outside for more than ten minutes. at least seven people have died

in several states as a result of the so—called polar vortex. research suggests a warming arctic is driving very cold air south from the north pole. neda tawfik reports. a steam fog settles over lake michigan, as the polar vortex grips chicago with the most extreme cold in a generation. temperatures fell to —30 degrees celsius and, with the windchill, it felt like —46 degrees, making it colder than parts of antarctica. you see this on my glasses? this is notjust fog, this is frost. it's ridiculous out here, and it's going to get worse. it's really freezing. it's really bad. yeah, it's dangerous. put layers on, make sure you're covered, and don't stay out too long. the polar vortex has sent arctic air across the midwest, affecting 50 million people. a state of emergency is in place in illinois,

wisconsin and michigan. authorities warn that the exteme temperatures are life—threatening, and thatjust minutes outside can lead to significant frostbite. we just want to make sure that people understand the severity of the weather out there, and that they are prepared. it's notjust the person who is risking it by getting outside. it is other people, that are first responders, who may have to show up on the scene. at least six deaths have been connected to the extreme cold. in several states, warming centres and shelters are open for the homeless and other vulnerable residents. hey, you need gloves! in minneapolis, police even handed out gloves to residents. businesses, schools and government officers have been shut, flights have been grounded and travelled disrupted. at chicago's union station, workers set fire to the rails to prevent them from freezing, using a built—in system that turns the tracks into a giant gas grill. and in grand rapids, michigan, white—out conditions were blamed

for two dozen vehicle crashes. ijust got caught in a giant wreck. the deadly deep freeze has brought life in the midwest to a standstill. it is expected to hover over the region for several more days, and scientists warn that, because of climate change, these exteme weather events could happen more frequently. neda tawfik, bbc news, new york. the british prime minister has begun her attempt, backed by a vote in parliament, to renegotiate her brexit deal. reports suggest there has been an open and frank discussion with the president of the european council. that is usually code for a stormy exchange of views. theresa may faces stiff resistance from european leaders, who insist the so—called backstop, to ensure there is no return to a hard irish border, must stay in place when the uk leaves the eu. this from our political editor laura kuenssberg. a different kind of meeting in his diary — the labour leader off to see his biggest rival. the prime minister leaving not to wrangle conservatives,

but to talk to him. reporter: will the eu make any changes? tea and biscuits served behind closed doors in her private office in parliament. but, after a0 minutes of talks, did the labour leader and the prime minister find any common ground? serious, exploratory on the issues, and i set out the labour case for a comprehensive customs union with the european union, in order to protectjobs in this country, and trade. reporter: can we find an alternative to the backstop? looking forward to the day today, thank you. the cabinet has already promised to redraft the arrangements for northern ireland. the backstop will have to change, and the prime minister will be negotiating with our european partners to get the very best dealfor britain. ministers will consider if the backstop, that insurance policy against a hard border, could have a time limit, or if the uk could leave when it likes, or that technology could be found to manage the border instead. but, even though she won the vote last night...

questions to the prime minister. ..the problem, the prime minister well knows, is that the eu has said no to all that before. the majority in this house voted to maintain the commitment to no hard border between northern ireland and ireland, to leave the european union with a deal, and to set out to the european union what it will take to ensure that this house can support a deal. that is a change to the backstop. that means there is, at least for now, a different mood here. tory backbenchers more used to tearing each other apart over brexit for once backing her, if she can get brussels to budge. tell the european union there is a majority in this house for that deal, and i would ask my colleagues to give the prime minister space. they're not going to crumble tomorrow. we're going to have to hold our nerve, and we can be successful. remember, the prime minister only narrowly got this place on side last night because she made a promise

that she would get part of her brexit deal changed. but wanting something to happen and making it happen are very different things. and, as far as the eu's top brass are concerned, at least in public, all 28 countries shook hands on the agreement, including the so—called backstop. so a deal is a deal, for now. the withdrawal agreement remains the best and only deal possible. european union said so in november. we said so in december. the withdrawal agreement will not be renegotiated. with the so—called backstop to protect the irish border affecting ireland, of course, the most, no surprise ireland is protesting most loudly about making a change. we in ireland are essentially being asked, as is the eu, to replace legal certainty, having negotiated that over two years, around british red lines, and to replace it with the hope

of something that has yet to be proven. listening to that, it is hard to imagine there is any mood to give the prime minister what she wants fast. but if there is to be a deal, one side or the other, in the end, will have to give. laura kuenssberg, bbc news, westminster. and, if you want to look at a useful guide to help explain brexit and what some of the terms like "backstop" mean, just go to our website bbc.com/news, or download the bbc news app. let's get some of the day's other news: president trump has lashed out at his own intelligence chiefs, who have contradicted his administration's line on iran and north korea. in evidence to a senate committee, they said iran was not seeking nuclear weapons and north korea was unlikely to give up its nuclear arms. the president described their reports as extremely passive and naive, and suggested they go back to school. saudi arabian officials are saying they have officially ended the anti—corruption drive that began in 2017 and saw hundreds of princes, tycoons and business chiefs rounded up.

it is claimed the state has recouped more than $100 billion in assets, including property and cash. at least 200 people have been held, many in hotels in riyadh. toxic smog in bangkok has forced more than 400 schools to close for the rest of the week to protect children. thailand's capital is experiencing some of its worst air pollution, and the authorities‘ efforts to clear the air have so far failed. traffic exhaust, burning crops and pollution from factories are being blamed. facebook users have continued to rise despite a series of data privacy scandals and criticism over its attempt to stem toxic content. fears that the company's scandals could put off advertisers also proved unfounded, with annual revenues up 30% on last year. user growth was particularly strong in india, indonesia and the philippines, but flat in north america. venezuela's president, nicolas maduro, has dismissed calls for new elections, but says he is prepared to talk

to the opposition to try to resolve the political and economic crisis wracking the country. it has been another day of anti—government protests called by opposition leaderjuan guaido, who last week declared himself interim president. 0rla guerin is in caracas for us. a student leader stands alone, pleading for a better venezuela. "it's what we all deserve," he says. "think about that when you go home tonight." the security forces remain impassive. they are likely to decide the future here. and for now, it seems they are standing with president nicolas maduro. but the opposition has its foot soldiers, young activists who feel a renewed sense of hope.

well, the students have brought their protest to the edge of the highway. the opposition here wants to keep up the momentum. it says it wants peaceful demonstrations and peaceful change, but there is a real sense here that this is a critical moment for venezuela, and everyone is aware of the risk of more bloodshed. larger protests are planned for saturday. the young activists we met believe their time has come. we were born in a dictatorship. we lived all our lives in a situation that gets every time worse, and this is the year that we feel we actually have an actual backing, international support. everything is colliding, so students are here to support the change in venezuela. the embattled president, nicolas maduro, popped up on state television. and he made sure to bring some friends. the message here — i'm going nowhere. but he said he was willing to talk to the opposition for the sake of peace. and, in a facebook address,

a warning for donald trump — hands off our oil. supporters of the president also on the move today, doing a drive—by outside a children's hospital. drowning out a protest by parents of sick children. two sides of the divide on display in caracas. but some were determined to be heard today, like romelo cabrera, a journalism student who had joined the protest on his walking frame. "i'm here for the same reasons as everyone else," he told me. "we feel bad for our country. it's painful to see what's going on. my sister and my cousin had to flee. i want them back. i want everyone to come back to a free venezuela." the students ended their

demonstration with the national anthem. "glory to the brave," it says. "down with the chains." this is a nation poised at a crossroads. 0rla guerin, bbc news, caracas. stay with us on bbc news. still to come: memories of biggin hill aerodrome. a new museum opens its doors to the public to tell the story of the raf air crews who were based there. the shuttle challenger exploded soon after lift—off. there were seven astronauts on board, one of them a woman school teacher. all of them are believed to have been killed. by the evening, tahrir square, the heart of official cairo, was in the hands of the demonstrators.

they were using the word "revolution". the earthquake singled out buildings and brought them down in seconds. tonight, the search for any survivors has an increasing desperation about it as the hours pass. the new government is firmly in control of the entirely republic of uganda. moscow got its first taste of western fast food as mcdonald's opened their biggest restaurant in pushkin square. but the hundreds of muscovites who queued up today won't find it cheap, with a big mac costing half a day's wages for the average russian. this is bbc world news. the latest headlines: the north—west united states continues to freeze as polar air brings record low temperatures. the european union insists it won't renegotiate britain's brexit deal, despite the vote in parliament

seeking changes to the so—called irish border backstop. more now on our top story. saira rana is a gynaecologist based in sycamore, illinois. thanks very much for your time. i know it has been rough and it is going to get rougher, isn't it, at record lows and head. that is correct, it has been extremely cold, and this is brutally cold, even today was. and we are targeting to break records set back way in 1985, which was the coldest day ever in chicago land. and i gather that is a time limit for avoiding frostbite when people go out, that has come down quite dramatically, hasn't it? that is correct, usually in temperatures, we are talking about fahrenheit, temperatures between 1a

and —17 it will take several minutes to one hour to get frostbite, but currently with the temperature below and the windchill bringing the temperature down even further, the chance of getting frostbite is between five to ten minutes on exposed skin. so, doctor rana, what does this mean for your business and the people you know? so, our town of syca more the people you know? so, our town of sycamore was literally closed today. schools are closed, universities are closed, even banks are closed. the police department closed and they are hoping to open for administrative work by noon tomorrow, when it is supposed to let up tomorrow, when it is supposed to let upa tomorrow, when it is supposed to let up a little. because of that, i closed my clinic for today, knowing that i see pregnant patients who usually come in with their little ones hanging with them because of school closures, and also older

females who have to find transportation to come and have a high risk of fall in the slippery cold weather. you know of course for many in the midwest it is kind of a badge of honour to make no big deal of the weather. we have heard people still cycling to work. but this is particularly rough. this is rough. it is rougher that what it usually is. and we are used to cold and snow. so that doesn't really bother us snow. so that doesn't really bother us here. except now the temperatures are arctic temperatures. and if you compare us are arctic temperatures. and if you compare us to alaska, sweden and norway, and after canada at this time, we are actually lower than them. doctor rana, you take care. thank you for talking to us. you are very welcome. stay warm. thank you, and you! more than 2,000 dehydrated flamingo chicks have been rescued from a drought—stricken dam in south africa and moved to rehabilitation centres — seems they were abandoned by their parents. kamfers dam, in the northern cape,

is one of the few flamingo breeding grounds in southern africa but rainfall is low and conservationists say poor infrastructure often makes the problem worse. kathryn armstrong reports. dinnertime for this flamingo chick brought farfrom dinnertime for this flamingo chick brought far from home. on the dinnertime for this flamingo chick brought farfrom home. on the menu todayis brought farfrom home. on the menu today is a liquid concoction of eggs, serial and prawns. it is one of hundreds of baby flamingoe that have been rescued from certain death after being abandoned by their pa rents. after being abandoned by their parents. ka mfers dam, after being abandoned by their parents. kamfers dam, just outside of the northern cape city of kimberley, is one of the few flamingo sentries in southern africa by the area is experiencing a drought. unable to fend for themselves, hundreds of chicks have been taken to a century in cape town where they will spend some months in care. so i think most of the birds that arrived were dehydrated. so they are very, very small. so in the wild their mothers would see them

every —— feed them very readily. they are transported in boxes, put on the plane, driven here. so obviously more than two hours had passed without being able to feed their chicks. so they were in very bad condition when they arrived. ita start to life, but it is hoped the birds will all make it to adulthood —— a tough. as for theirfuture it is not yet clear whether flamingos will be released in cape town or taken back to their natural home. 99 people are confirmed dead in the area of brazil where a dan cole axed last friday. 200 people are missing. it is another incident that has occurred with the vale company in the last three years. the human rights council has called for a thorough investigation. the california board of parole has again recommended that the youngest member of charles manson's gang be freed from prison. leslie van houten is serving a life sentence for her role in the colts killing spree in 1969

when she was 19. the authorities have twice overruled the boa rd's recommendation to release van houten, who is now 69. there's been a big rise in the number of monarch butterflies making their annual migration from canada, through the us to mexico. the species hit an all—time low in 2014, sparking a tri—lateral conservation effort to protect the butterfly and its habitat. this year, there's been a 144 per cent rise in numbers. i sopke tojorge rickards a little earlier. that's right. indeed, we are very happy to share this news today. it is over six hectares of colonies of overwintering monarchs, the monarchs have flown from canada 2500 miles to get here and spend the winter in mexico. and it's very exciting indeed, because last year we had only 2.4 hectares. as you said, it is a 144% increase. this gives us hope that we might begin to see a recovery in the population of the eastern migrating population of the monarchs. is always amazing to think

of something apparently so delicate doing that kind of migration. why is the monarch butterfly so important? well, as an insect it is a pollinator and, in general, we are seeing a pollinator crisis all over the world. just by itself it is important to be concerned. it is a symbol in conservation as something that unites three countries. it is one of those elements that has promoted collaboration between canada, the united states, and mexico. it also involves very direct work with local communities concerning their forests here in mexico. people in the us and in canada are helping to create or rebuild habitat for the monarchs and it's a very powerful symbol and also because the conservation of the monarch butterfly is beginning to show good results here, as in the united states. so it is encouraging in a context in which all the world needs to be

very, very concerned about our environment. on that point, i think there were a point of local people in mexico stopping illegal logging to help the butterflies. yes, that's right. actually, we have been working in the reserved for 25 years and in the last 14 years we have been working very, very closely with 33 local communities. these are indigenous communities, mostly, that depend on the forest, they live within the biosphere reserve and they have made a very serious commitment to conserve the forest and what we have been doing is helping them find ways to have a sustainable livelihood, getjobs in saving the forests, and, altogether, this effort has led to a very important decrease in illegal logging. several years ago, around ten years ago, we had around 400 hectares of illegal logging a year. at that rate we would not have a forest anymore, a forest reserve. in the last four years we have literally eliminated is illegal logging. it is good to maintain a good forest and ecosystem for the monarchs to arrive and overwinter here in mexico.

cheerful news for a change. jorge rickards a little earlier. biggin hillis one of britain's oldest aerodromes. during the battle of britain, churchill called it his strongest link. pilots from the airfield shot down almost 1,500 luftwaffe aircraft. now a new museum has opened its doors to the public to tell the story of the raf aircrews who were based there. 0ur correspondent duncan kennedy reports. if an air battle can have a front line, the skies over biggin hill was it. in 1940, raf pilots held that line against the germans, including the late geoffrey welham. i always felt that if i could see my antagonist, i could out fire him in a spitfire, and that was the big thing. see him, out fly him, fight him. biggin hill's new museum now tells these stories for the first time. like elspeth henderson, who hid under a table during one attack. the bomb bounced off the table

itself before exploding. the blast shattered the glass and the windows and the plotting table before setting the building on fire. 0r geoffrey greensmith, who met a wounded german pilot after he was shot down. he had photographs of his two children. one was the same age as me. that upset me. yeah, it still does. but biggin hill wasn'tjust a place about aircraft and bombs. through these letters, it also became the location for romance and love. lillian simpson and keith 0gilvy stayed sweethearts by writing, even when he became a german prisoner of war. we don't talking in the language of victor and villain, we are sharing people's real human experiences and, hopefully, inspiring our visitors by showcasing the very best of human spirit. biggin hill stood for defiance — an airfield and its people who saved britain.

duncan kennedy, bbc news. a video of a tourist in australia holding a very small, quite colourful octopus in their hand is getting rather a lot of hits on the net. because the apparently unknowing traveller was palming one of the world's most venomous marine creatures, the blue—ringed octopus. experts say it holds enough venom to kill up to 20 people, although the good news — kind of — is that its actual bite is painless. social media commentators expressed their shock and concern over the video. "this is how tourists become statistics," said one reddit commentator. another said, "i heard about one case where the person was paralysed and could hear the first responders discussing whether they should continue compressions or not." and this, too, "it should be mandatory viewing on the plane over to australia that our wildlife is not to be messed with." just briefly, the midwest of the us

is still freezing and it is likely to get worse as polar air brings record low temperatures. a warming arctic is pushing particular cold air south from the north pole. much more on all of the news any time on the bbc news website. and you can get in touch with me and most of the team on twitter. thank you for watching. hello there. we've got a potentially disruptive snowy spell of weather on the way. we've got very cold air locked in place and an area of low pressure developing over the atlantic. and it's a perfect breeding ground for a snow event as this moisture moves in across the country, bumps into the cold air — some of us are likely to see some pretty heavy sleet and snow through thursday into friday. so of course some yellow warnings are in force for snow, ice, and also the risk of freezing fog overnight through thursday into friday, it's likely to cause some disruption so stay tuned to bbc local radio and keep tuned to subsequent weather forecasts.

but we start this morning on a very cold note, largely clear skies. so many places will be dry. a few wintry showers continue across the north of scotland. we'll also see some freezing fog patches developing. something else to watch out for. we could be looking at temperatures as low as —12 to —15 celsius in some of the scottish glens. so we could have ice and also risk of freezing fog to start this morning. but, on the plus side, plenty of crisp winter sunshine. now, things start to go downhill across the south—west of england across wales and that weather system arrives, initially bringing rain and turning increasingly to snow across this part of the country. further north and east it should be relatively dry. the sunshine continuing. but it will be a cold day with increasing easterly winds. now this sleet and snow will gather force and become more widespread, pushing northwards and eastwards all the while through thursday evening and overnight. some heavy snow likely across the downs of the south—east into the midlands and certainly across southern and eastern parts of wales. by early friday this

is the lying snow, a map. we could be looking at significant accumulations across parts of wales, the south—west, and the south downs, 1—4 centimetres to lower levels. a lot more than that further north. so a significant risk of ice through friday night. rain, sleet, and snow will continue to fall, become lighter and patchier, but it'll still continue to accumulate in places. we'll see wintry showers across the north—east of england and further wintry showers across the north of scotland. it's going to be a very cold night again, a significant risk of ice. now, our area of low pressure gives to migrate southwards, taking its weather fronts with it. so we'll start to see a slow improvement across the south of the country. but we could still see some rain, sleet, and snow continue for a while throughout friday. this easterly breeze will bring more wintry showers into eastern england and eastern scotland, further wintry showers across the north of scotland. but in between we should see plenty of sunshine around, but that really won't do much for the temperatures. it is going to be another cold day. but stay tuned to the weather forecast. this is bbc news.

the headlines: millions in the american midwest are experiencing a blast of arctic air so ferocious they are being warned they risk frostbite if they stay outside for more than ten minutes. at least seven people have died in several states as a result of the polar vortex. many businesses and schools are closed. european union negotiators are insisting they won't reopen britain's brexit deal, despite the vote in the uk's parliament seeking changes to the so—called backstop. they want it in place to ensure there is no return to a hard irish border when the uk leaves the eu. more street protests in venezuela. president maduro is still refusing new elections, but says he is willing to sit down to talk to the opposition. president trump has offered his personal support to the opposition leader, juan guaido, in a phone call. now on bbc news, hardtalk.