The Royal Free Hospital says it is coping with the heatwave by issuing water to patients and staff.

The Pond Street hospital has issued "emergency planning advice" to staff to safeguard high-risk vulnerable patients.

This comes as a heatwave swept across the country, with temperatures exceeding 40C in London on Tuesday for the first time recorded.

A Royal Free London spokesperson thanked staff "who are working hard to reduce the impact of the heatwave on our patients and colleagues".

"Appointments at the Royal Free London are continuing as planned this week, however if patients feel they will be at risk travelling to their appointments, we recommend that they contact us to rearrange," they said.

"Our emergency planning colleagues have issued advice to staff to ensure that high-risk, vulnerable patients are monitored more frequently and kept well hydrated.

"We have also issued guidance for keeping workplaces cool and have signposted staff to cooling areas in our hospitals.

"As well as taking precautions to keep our hospitals safe in the extreme heat, water was handed out to staff and patients to keep them hydrated.”

Hospital chiefs did not say how under pressure they were.

However, on Wednesday (July 20), the London Ambulance Service released a statement highlighting a surge in the number of calls it had received, roughly one every 13 seconds.

The statement said: "Over the last two days, the London Ambulance Service has taken a total of 13,400 calls to 999, with 6,600 on Monday (July 18) and 6,800 on Tuesday (July 19).

"This equates to one every 13 seconds.

"By comparison – and prior to the pandemic – we would take 5,500 calls on a very busy day.

"Early data shows that on Tuesday, we saw a ten-fold increase in incidents related to heat exposure compared to the previous week, and an eight per cent increase in people fainting."

It asked people to keep out of the sun between 11am and 3pm, wear sunscreen and drink plenty of water.

Brian Jordan, director of 999 operations, said: “We really need the public to continue to support us over the coming days – whilst it won’t be as hot, it is still predicted to be very warm with temperatures of around 26C for several days.

“I would like to thank the public for their help and support over the last few days and to publicly recognise the hard work and commitment of our staff and volunteers.”