The London Ambulance Service (LAS) said on 20 June 2025 that it had activated its plans for high demand ahead of a weekend forecast to be hotter than the previous one. The service reported receiving more than 7,000 calls on some days in the preceding week, against 5,500 on a typically busy day1.
The LAS said last Friday high pollen levels and warm temperatures meant it received more than 7,000 calls, and that this weekend was forecast to be even hotter. Its Director of 999 Operations, Stuart Crichton, said the figure was nearly an additional thousand 999 calls a day compared with the same period last month1.
The activated plans include extra ambulance crews out on the road and extra call handlers in control rooms. The service said it was also maximising other forms of care, such as community response cars, having more clinicians assess patients over the phone, and working with hospitals so patients are handed over more quickly1.
"We have been very busy this week and expect to be even busier this weekend as temperatures climb even further. We would will like to remind Londoners to only call 999 in a life-threatening emergency."
The service asked people to use it wisely and to contact a GP, pharmacy or NHS 111 where possible. Crichton said older people, the very young and people with pre-existing conditions are more at risk in hot weather, and asked people to look out for neighbours, family or friends who may need help and to make sure they can keep cool. He added that people sometimes start to feel ill a few days after hot weather1.
The LAS advice quoted by the service includes avoiding prolonged exposure to direct sunlight, especially between 11am and 3pm when UV rays are strongest, sticking to shade and wearing sun cream; drinking plenty of water and taking a bottle when heading out; and, if drinking alcohol, having a meal and soft drinks as well1.
Why it matters for households
The warning covers London, where the ambulance service says demand has already run at nearly a thousand extra 999 calls a day on some days. The groups the LAS names as more at risk in hot weather are older people, the very young and people with pre-existing conditions, and the service asks households to check on neighbours, family and friends who may need help keeping cool1. The service's own guidance on when to seek help is set out in the site's page on when to call 999 or NHS 111 for heat illness, and its description of how services respond to hot weather is covered in the Adverse Weather and Health Plan. Practical steps for households are listed in the hot weather preparation checklist, within the heatwaves and drought section.
What happens next
The LAS said it expected to be busier over the weekend as temperatures climb further, and that its teams remain available for life-threatening emergencies while asking people to contact a GP, pharmacy or NHS 111 where possible1. No further dated steps were given.
Adverse Weather and Health Plan
Hot Weather Preparation
Calling 999 for Heat Illness
