The London Ambulance Service (LAS) is under pressure after it responded to 4,500 emergency calls by 5pm on Friday as the global IT outage hit the NHS, the chief executive said.
Some patients who would normally have gone to their GP or a health centre have been forced to call 999 because those services have been hit by the software problem.
It comes as searing temperatures in the capital, with a reading of more than 31C at Heathrow, put further pressure on the LAS on Friday.
The 3,000 calls received before 2pm on Friday are a third higher than a normal 24-hour period. The number increased to 4,500 by 5pm.
Chief Executive of London Ambulance Service Daniel Elkeles said: “We continue to be exceptionally busy having taken 4,500 999 calls at 5pm and 111 is also under a huge pressure.
“So please do only use us wisely and bear with us because it will take us longer to answer the phone and get a response to you.”
He said earlier: “Following the global IT outage that has impacted some NHS services across the capital, our call handlers and ambulance crews are incredibly busy with huge increases in the number of calls to both our 999 and 111 services.
“Our teams are always here to help if you need us and we encourage anyone who needs our services to continue to contact us.
“We are working very hard to make sure we are getting to patients as quickly as possible, but please be aware that our response times today may be impacted by this global issue.
“We ask that people use our 999 services wisely and contact their pharmacy or visit NHS 111 online where possible. Londoners can continue to help us by only calling 999 in a serious medical emergency.”
The problems have been mirrored by other ambulance services across the UK.
The South East Coast Ambulance Service has declared a “business continuity incident” and is experiencing “increased pressure” across its 999 and 111 services due to the global IT outage
A spokesperson for the service said: “The majority of our infrastructure is unaffected and we are continuing to respond to patients.
“However, we do not have access to some external NHS services and have declared a Business Continuity Incident to manage our response.
“We are experiencing increased pressure across both our 999 and 111 services and prioritising our response to our most seriously ill and injured patients.
“We ask for the public’s support in only calling 999 in an emergency and by making use of alternatives including using NHS 111 Online for help and advice.”
