London Ambulance Service has reported that the June heatwave produced the busiest week in its history, with more than 53,000 emergency calls and a record number of Category 1 incidents, which include cardiac arrests and patients who had stopped breathing1. The Service said the call volume surpassed demand seen during the peak of the Covid-19 pandemic, and that it deployed 600 additional ambulance crews across London1. The figures were published on 13 July 2026 alongside new analysis of heat deaths1.
The same analysis, from the Met Office, Imperial College London and the London School of Hygiene & Tropical Medicine, estimates that around 2,700 excess deaths occurred across England and Wales during the May and June heatwaves1. Earlier in the summer, the Service reported that call handlers received 8,121 999 calls on Tuesday 26 May, an increase of 38 percent compared to 5,874 calls on the Tuesday the week before, making it the sixth busiest day in its history2. Crews also attended the highest number of patients out on the road since the start of 2026 on the preceding Monday2. The Service activated plans known as REAP 4, which include maximising other forms of care such as community response cars, having more clinicians assess patients over the phone, and working with hospitals to hand patients over more quickly2.
Call handler Marcus Donnelly worked on what the Service describes as the busiest day in its history, 26 June1. Call handler Asha Patel said she took 90 calls on the Friday and 93 on the Saturday, adding: "I have never gone above 60 calls on a 12-hour shift"1. Paramedic Mary Byrne said the Service was seeing an increase in patients experiencing dizziness, vomiting and lethargy1.
"During the June heatwave, London Ambulance Service experienced the busiest week in its history and responded to a record number of Category 1 incidents, which includes cardiac arrests and patients who had stopped breathing."
| Measure | Figure | Period |
|---|---|---|
| Emergency calls received | More than 53,000 | June heatwave week1 |
| Additional ambulance crews deployed | 600 | June heatwave1 |
| 999 calls in a single day | 8,121 | Tuesday 26 May2 |
| Rise on the same day the week before | 38 percent (from 5,874) | 26 May2 |
| Estimated excess deaths, England and Wales | Around 2,700 | May and June heatwaves1 |
Why it matters for households
The Service's figures show how quickly sustained heat can translate into emergency demand, and who is most affected. It states that older people, the very young and people with pre-existing conditions are more at risk in hot weather, and encourages people to check on neighbours, relatives and friends who may need help keeping cool2. It also reports that calls relating to difficulty in breathing, dizziness and fainting rose, along with more calls about chest pains and heart problems, and that respiratory and cardiac-related calls are common in the days following a heatwave2. The Service advises people to drink plenty of fluids, avoid excess alcohol, stay out of the sun between 11am and 3pm, keep homes as cool as possible and avoid strenuous activity such as running during the hottest parts of the day1. It asks the public to call 999 only in a life-threatening emergency, and to use NHS 111 or NHS 111 online, or contact a GP, for urgent medical advice1. It advises calling 999 if someone is experiencing difficulty in breathing, confusion or a reduced level of consciousness1. The Service's guidance on heat and its effects sits alongside wider household heatwave and drought planning.
What happens next
No further dates have been announced. The Service says temperatures remain high and urges Londoners to take the heat seriously1. It notes that people sometimes start to feel ill a few days after hot weather and asks the public to continue looking after themselves and others2.
Sources (3)
- London Ambulance Service urges Londoners to keep safe as research reveals deadly impact of extreme heat - London Ambulance Service NHS Trust, londonambulance.nhs.uk
- “Only call 999 in a life-threatening emergency”: London Ambulance Services faces busiest day since the pandemic - London Ambulance Service NHS Trust, londonambulance.nhs.uk
- “Only call 999 in a life-threatening emergency”: London Ambulance Services faces busiest day since the pandemic - London Ambulance Service NHS Trust, londonambulance.nhs.uk
