London (CNN) British doctor Katie Sanderson hit breaking point over the weekend. As she advised the family of a Covid-19 patient on where their loved one should die, she received an image on her phone of crowds of people sunning themselves in a north London park.

"That made me hit a wall," the 32-year-old said, furious that members of the public were not heeding the government's social distancing advice as confirmed cases and deaths from the global Covid-19, or coronavirus, outbreak climbed in the UK. "These people are going to contribute to somebody needlessly dying in two weeks' time."

The rapidly rising number of deaths in Italy and Spain have placed Europe at the epicenter of the coronavirus crisis. Both countries now have higher death tolls than China, where the outbreak began, and with more than 7,500 fatalities Italy has the most deaths anywhere in the world.

British Prime Minister Boris Johnson said last Sunday that the UK is only "two or three" weeks behind Italy, and warned that its National Health Service (NHS) could be "overwhelmed" by the virus, like its continental European counterparts. The following day, Johnson imposed the most stringent restrictions seen in Britain since the end of World War II, after it became clear that advice about social distancing was not being adhered to.

The country's health workers are now bracing for a wave of Covid-19 patients. Sanderson's hospital, the Whittington in north London, is one of a number of UK facilities that has already attempted to scale up capacity and transform the way it is being run, in an effort to accommodate an increase of arrivals in the past week. An emergency medicine registrar at a north London hospital, Dr. Robert Lloyd, returned from holiday this week to find his department had changed radically. "Over the last few days, it is empty in the morning and in the afternoon it gets flooded, literally flooded, completely at capacity, and all patients are almost perfectly positive [for coronavirus]."

This mirrors the situation at south London's King's College Hospital, which has spent weeks training staff and converting wards into intensive care units, according to a critical care worker, who wanted to remain anonymous out of concern that speaking publicly would put their job at risk. They added that the caseload "has been pretty unprecedented." King's College Hospital told CNN that it has been "training staff as required to be redeployed to support teams who are treating patients who test positive for Covid-19 as well as increasing bed capacity."

CNN has spoken to more than a dozen health workers across England -- management of the NHS is devolved to the UK's four constituent nations -- who are anxious about how the disease will run its course in the country's much-loved but chronically underfunded health service . The case numbers are already increasing rapidly at hospitals in London, where coronavirus cases are rising faster than anywhere else in the country.

King's College Hospital in south London has been scaling up for the outbreak.

Chris Hopson, head of NHS Providers, which represents hospital administrators, said London was facing a "continuous tsunami" of coronavirus patients. In an interview with BBC Radio 4 on Thursday, Hopson said London hospitals had increased critical care capacity by between five and seven times in the past few weeks, but are now struggling to meet the "explosion of demand."

In a statement to CNN, Hopson said the outbreak "is by far the biggest challenge the NHS has ever faced in its history and it is striking how everyone is pulling together to prepare for the explosion in demand that is going to come."

The critical care worker at King's said the main message that London health professionals want to get out to hospitals that have yet to be hit by cases is: "Do the preparation, because without it you won't be able to cope."

Rising anxiety

Faced with a global pandemic, capacity was always going to be an issue for the NHS. The UK lags behind most OECD countries with just 2.1 acute hospital beds per 1,000 people . Germany, by comparison, has six beds for every 1,000 people. And while NHS England is one of the world's biggest employers, with 1.5 million people on staff, prior to the pandemic (between July and September 2018) it had 94,000 full time roles unfilled -- many of them in nursing.

The British government, criticized for its less aggressive start in responding to the pandemic, has been attempting new measures to flatten the curve of new Covid-19 infections after a high-profile study found that coronavirus could overwhelm the number of intensive care beds and lead to 250,000 deaths in the UK.

In a letter published March 17 , NHS Chief Executive Simon Stevens said it was going to "free up 30,000 (or more) of the English NHS's 100,000 general and acute beds," by postponing non-urgent operations, discharging medically fit patients, and "block-buying capacity" at private hospitals.

London's Excel Centre -- an exhibitions and conventions venue better known for its culinary fares and art exhibitions -- is being repurposed into a temporary hospital for 4,000 coronavirus patients , Health Secretary Matt Hancock announced Tuesday. As confirmed cases topped 6,000 in the UK, as well as more than 400 coronavirus-related deaths, as of Tuesday Hancock said that almost 12,000 former health staff had agreed to return to help out with the crisis.

London's Excel Centre is being turned into a temporary hospital.

At the regular Downing Street briefing the following day, England's chief medical officer Chris Whitty said the NHS had been working hard to boost capacity in the system by "pushing out in time things which can be postponed and increasing critical care, and particularly the ventilated bed capacity, over the next week."

He said the present level of demand on hospitals was no worse than a normal winter day, but the number of cases was expected to rise and fighting the outbreak was "going to be a close-run thing" for the NHS.

The government is also attempting to plug the shortage of ventilators in the UK. Hancock told the BBC on Monday that the NHS now has access to 12,000 ventilators, up from 5,000, and manufacturers were going to step up production of the respiratory aides.

It was unclear how many of the 12,000 were immediately available, and in any case more ventilators require more staff to operate then. "There is no point having ventilators if you don't have skilled people using it," Dr. David Oliver, a senior consultant in geriatrics and acute general medicine at a hospital in southeast England, told CNN.

And while English hospitals undergo a "major effort" to expand intensive care beds, they are also training staff. "What is happening all round the country is any nurse who had previous intensive care experience -- we are trying to get them upskilled again," Oliver said, adding a potential problem could be the current standard ratio of one nurse to one intensive care patient may have to be relaxed when hospitals hit peak capacity.

The virus appears to impact older people much harder than younger patients. But Lloyd, the north London doctor, told CNN that 30-year-olds were among the seriously ill patients he saw this week, whose x-rays "look like a bomb had gone off on either side of their chest."

Dwindling supplies

Health workers across England have been sounding alarm bells about dwindling protective equipment. Nearly 4,000 doctors warned the government on Sunday that they could become "cannon fodder" for the virus due to inadequate PPE, according to a letter coordinated by the The Doctors' Association UK ( DAUK), a group that lobbies for frontline NHS workers.

DAUK told CNN Thursday that around 50 doctors have said they have no personal protective equipment (PPE), such as masks, gowns and gloves, and have had to buy their own on eBay or at DIY stores.

The British Army has been deployed to deliver protective equipment to hospitals.

He added that doctors outside London have also struggled to gain access to scrubs, which are typically only used in intensive care operating theaters. "There's been no consideration for people who don't want to be wearing their own clothes [at hospitals] -- health workers want to change into scrubs so that they don't take that infection back home with them," Dr Rinesh Parmar, chair of the DAUK, told CNN.

Family doctors, who in the UK are based in the community and are the place where most people turn first when they feel sick, say they feel neglected in this crisis. Two who CNN spoke to said that they are still conducting home visits without proper PPE.

The government said 7.5 million pieces of protective equipment has been shipped out, but Dr. Pallavi Devulapalli, a general practitioner, told CNN that her practice in rural Norfolk has yet to receive new supplies. "What keeps me up at night is that the hospital will be flooded, and that very ill people will have nowhere to go; and we will have to manage them in the community," she said.

Doctors also complain that Public Health England (PHE) guidelines on protective equipment are not as stringent as World Health Organization (WHO) advice. PHE recommends that a health worker dealing with a suspected Covid-19 patient should wear an apron, surgical mask and gloves, as well as protective glasses if there is a risk of splashing. The WHO recommends a full gown and visor at all times.

"It worries people because we don't have a clear reason" for that discrepancy, said Dr. Adam Collins, an emergency doctor in central England.

"We're hearing from colleagues across continental Europe about what they're facing, they are a few weeks ahead of us and telling us, "you need the right protection and you need to you need to be prepared," Parmar said.

"And we are not prepared, we don't have the right PPE yet the government still says: 'we've got adequate stock levels in the pandemic stockpile,'" he added.

On the frontline

Health workers are falling sick, or having to self-isolate due to someone in their household displaying flu-like symptoms, even before the expected surge of UK infections. The problem is made worse by the lack of available testing to help determine if they have the virus or have developed immunity to it. On Friday, the BBC reported that a doctor in Essex, outside London, died after showing "textbook signs" of the virus.

Official statements on testing have been contradictory. An official from PHE, Sharon Peacock, told a parliamentary committee on Wednesday that the government could be days away from rolling out an at-home test for COVID-19 antibodies, which would allow people to check if they'd had the disease. England's chief medical officer, Whitty, poured cold water over the claim on Wednesday. "I do not think, and I want to be clear, that this is something you will suddenly be ordering on the internet next week," Whitty said.

Chris Whitty has taken part in many of the daily Downing Street briefings.

The government says testing capacity is being ramped up but health workers say it has not happened fast enough. Collins, who is 28, spent Tuesday morning writing his will after it was announced that 23 Italian doctors had died since the outbreak started. That toll increased to 37 on Wednesday, according to the Italian federation of doctors.

Frontline workers have had to rely on models, rather than testing data, to help estimate the surge in caseload in the coming weeks. Parmar, from DAUK, said Britain had "abandoned testing in the community so we really don't know what our population contamination and infection rates are."

"Think about it, we are testing between 8,000 and 10,000 patients a day -- but we need to be in the hundreds of thousands by now, and the UK has had a head start, we knew this [virus] was coming," Parmar said.

Comparing the UK's testing response to other countries is unhelpful as their outbreaks have a "different epidemic pattern," Whitty said Wednesday, adding that screening people from high-risk countries had ceased to be a sensible policy.

"We moved onto testing people in intensive care and in hospitals...that system is working fine and is being scaled up," he added. While testing of NHS staff and critical workers needed to grow, he explained that the UK was contending with supply shortages due to high global demand.

Dr. Partha Kar, a consultant at Portsmouth Hospitals NHS Trust, says he worries about infecting his loved ones. "Personally it has been a little bit tough because my mum and dad have come here from India to celebrate their 50th wedding anniversary -- so now they're trapped," he said, adding that his house has been split into zones in an attempt to social distance from his parents.

Some health workers say they dread the point when they will have to begin making ethical decisions currently being made by their Italian colleagues. An Italian doctor at Salvatore Hospital in L'Aquila told CNN that a lack of equipment was forcing colleagues to triage patients, choosing the young over the old because of the probability they are more likely to live.

"It is absolutely terrifying to think that there could be someone in front of you that you've got the medicine to be able to treat," the critical care worker at King's said. "But if you have one bed left in the hospital: do you treat the 60-year-old that's got kidney failure and diabetes, or do you treat the 30-year-old who is normally fit and healthy?"

Health workers say a full accounting of official failures will have to wait for now. They are too busy preparing and taking part in practice drills on how to save lives. They were, however, unreserved in their criticism of certain companies and members of the public who have chosen to flout social distancing rules despite official advice.

"I think people have been selfish," Dr. Stuart Hanmer, a junior doctor working in central England, told CNN. "They have to take this matter into their own hands, and help us, the NHS, to slow down the course of this virus."

As the days tick down, many spoke in war analogies as they waited for the unprecedented peak of infections. "It feels like when the soldiers are preparing for battle, before the sound of the horn," Dr. Bogdan Chiva Giurca, a junior doctor at a hospital in Surrey, just outside of London, told CNN.

Lloyd, the north London registrar, said he was "frightened for the implications the virus has for society, it is going to have a major impact and a huge body count." He added that he is ready for battle, however. "From a professional standpoint, this is a defining moment for most of us -- so much of our training has set us up for this."