Image copyright Whittington Health NHS Trust Image caption Meals for the NHS helped deliver free food to these workers from the Whittington Health NHS Trust

As NHS doctors and nurses in intensive care units across the UK battle to save as many lives as they can, outside their hospitals, networks of volunteers are ensuring these key workers get fed and know they are appreciated.

"You can't save an entire nation on an empty stomach," says Alick Varma, a tech entrepreneur and one of the co-founders of Meals for the NHS.

It is one of the grassroots organisations popping up in an attempt to ensure that no NHS worker goes without food during the coronavirus crisis.

In just a few days, he and his other co-founders have raised more than £200,000 and set up a network to deliver to 17 hospitals in London, providing free hot meals to NHS staff.

The food hasn't gone just to doctors and nurses but to others playing a vital role in keeping the hospitals running - from security guards to cleaning staff.

Image copyright Meals for the NHS Image caption The Meals for the NHS team have been co-ordinating using Whatsapp and other apps in a bid to keep their social distance

Mr Varma adds: "On Sunday I was talking to a doctor friend and when I heard how staff were doing 18-hour shifts - and it's not that they don't have canteens, it's just the canteens weren't really open or there wasn't anything on offer other than something they could grab from a vending machine - it really hit home the need to get meals to doctors and nurses."

The team has already provided hungry NHS workers with several thousand free meals. Its members are in the process of applying to become a charity but at the moment have set up as a company to help them organise logistics.

Andrew Muir Wood, one of the other co-founders, says they have made sure to team up with businesses close to the hospitals, as they wanted to help the communities and local economies to continue to thrive during the lockdown.

They are not the only ones, though.

Image copyright Daksha Varsani Image caption Daksha Varsani's team has been delivering meals to hospitals across London, including Barnet

In Wembley mother-of-three Daksha Varsani has galvanised an entire community to help make Indian meals and sandwiches to send to hospitals in London and beyond. She's set up the Covid-19 Response Kitchen.

Mrs Varsani, who is from Newham, said she was moved to take action after watching a video posted by Yorkshire nurse Dawn Bilbrough, who was left in tears after being unable to find or buy any essential supplies after a gruelling shift.

"I saw the video and then decided something had to be done," she said. "Lots of family and friends offered to help after I put a post up on my social media and it's snowballed from there."

After tracking down two chefs with the correct food certifications, a batch of 50 meals was sent to staff at London's Northwick Park Hospital, where her niece is working in its Covid unit.

Then she teamed up with Desi Dhaba, a restaurant in Wembley, and Katie-Louise Barber, a mother-of-three from Barnet who was also fundraising. They spread the word so that more and more people and businesses got involved and more deliveries were sent to hospitals across the capital.

So far, they have delivered at least 5,000 free meals and are looking to expand further.

Mrs Varsani said: "People want to help. There is a demand and we want to meet it. We've seen nurses crying and telling us this is something they need."

But she stressed that it was imperative that those making the food they were delivering to the hospitals had the right certification, such as local-authority registration and food-hygiene certificates, plus the correct insurance.

"Only the chefs cook... All volunteers wear masks, hair nets, aprons while handling food." She said they followed a "strict" regime washing hands, sanitising and wearing gloves.

Image copyright Double Bubble Tea House Image caption Tea house owners packed up boxes of bubble tea to take to Peterborough City Hospital

Meanwhile in Peterborough, Aleksandra Zarnowiec and her husband, Pawelco, are now planning to deliver free bubble teas to hospital staff weekly. The couple, who own the Double Bubble Tea House, say it is an opportunity to give back.

Ms Zarnowiec said: "We were pretty much forced to close because of the government lockdown so all we can do is deliveries.

"We were trying to think about what we could do to help and thought, well the only thing we know how to do is to make good bubble tea, so let's give that to the hospital workers."

Image copyright Ros Paterson Image caption Ros Paterson's offer to make food for her local hospital while keeping her business open has been well received

In Inverclyde, baker Ros Paterson's ovens are rarely off. She thought her business was at risk after the Scottish government told cafes and gyms to close.

But when a friend asked to buy a box of brownies to send to staff at Inverclyde Royal Hospital, it set up a chain of human kindness.

"I put a post up on social media and said if people want to buy a box of brownies at a 40% discount, I'll deliver them for free to the hospital. In the first day about 40 boxes were ordered. I thought a few orders would come in but not so many. People were sharing [the post] left, right and centre.

"It's helping me to retain my sanity, even if I'm not making much money from it. It's giving people a way to give back."

The sole trader added: "We have to take care of the people who take care of us."

Of course, they are not the only ones. Fundraising pages are being set up nationwide for local and regional initiatives.

In Cardiff, traders calling themselves Holy Yolks have set up a Help the Heroes campaign and far exceeded their £200 target for a weekly shop for NHS staff.

Al Maidah is providing 1,000 meals a week for NHS staff at North Manchester General Hospital; Nandos staff have dropped off food parcels at hospitals around the country, while volunteers from Khalsa Aid have taken hot meals to exhausted NHS staffers, too. Fast-food chain Leon has launched a not-for-profit campaign called FeedNHS.

Hospitals around the country have gratefully accepted the food parcels and staff have taken to social media to say thanks personally. However, some hospitals have been so inundated they've had to ask people to stop the deliveries for now.

All the organisations that have emerged say they need help to sustain the demand, especially during these uncertain times.

Andrew Muir Wood, of Meals for the NHS, said: "We've estimated that we need to raise £1m of funding just to feed the hospitals we already have on board for the next 90 days."

If you want to Make A Difference get in touch with your BBC Local Radio station at bbc.co.uk/makeadifference