More than 400 mourners given "care" by St John Ambulance since Queen's death

Since the Queen's passing last week, the charity has provided "care" for more than 400 people, with more than half that number treated on Wednesday when the Queen's period of lying-in-state began.

Queues of up to 30 hours are expected for people wishing to pay tribute to the Queen at Westminster Hall, where her coffin will remain until the state funeral on Monday.

And to keep people safe while they line the streets in mourning, the charity has issued key advice for people heading to the capital:

• Wear comfortable shoes and clothing

• Stay hydrated and bring snacks

• Be prepared for all weather conditions – the forecast is for warm days and much cooler nights, with temperatures dipping into single figures

• Seek medical help from St John volunteers if you are injured or feel unwell.

While a small number of patients have presented with serious conditions, the most common complaints include blisters, dehydration and feeling faint.

Dr Lynn Thomas, St John Ambulance’s medical director, said: "We’re proud and privileged to be providing first aid cover during the period of national mourning, and pleased to be on hand if people need our care, but there are simple ways you can plan ahead and make sure you're prepared to look after yourself and others.

“Packing extra clothes - especially socks – and bringing waterproofs, and an umbrella for rain which can also be used to help shade from the sun. Try to keep your feet dry as this will help maintain your core temperature.

“For those waiting overnight, it is starting to get chilly, so wrap up warm. Consider bringing multiple thin and thermal layers rather than heavy, bulky jumpers as these can draw heat away from your body.

"As well as wearing comfy shoes, packing blister plasters is also something I would recommend strongly."

Dr Thomas added: “Make sure to bring plenty of food and water to keep yourself hydrated. We’re seeing instances of people fainting, but you can reduce your risk by making sure you’re eating and drinking regularly to help regulate blood sugars.

"If you have a condition which is medicated, please ensure you bring enough of your essential medication – for example make sure you have your epi-pen, or medical equipment with you too.

"This is a difficult time for many, and the news can affect people in different ways. So, look out for one another, and if you're upset and struggling emotionally, please do reach out for help and talk to someone.

“Lastly, but most importantly, please head for a St John Ambulance treatment centre or first aid point, or look out for one of our volunteers, if you or someone you’re with is injured or feeling unwell."

As the nation marks the loss of Her Majesty Queen Elizabeth II, around 2,000 St John Ambulance volunteers have offered their support with the lying-in-state and funeral.

The charity has 30 treatment centres in London – including along the route to the lying in state at Westminster Hall – with highly trained volunteers and healthcare professionals on hand to support people’s medical needs.