An emergency planning exercise preparing London for a return of 40C heatwave was being held on Thursday.
Temperatures in the capital hit a record 40.2 Celsius in July 2022 and the London Fire Brigade saw its busiest day since the Second World War tackling more than 200 wildfires.
Operation Helios, which is being run by City Hall, will test the readiness of emergency service and health organisations to come to the aid of Londoners in the event of five consecutive days of extreme heat.
Soaring temperatures pose a critical health risk, especially to the elderly, babies and people with breathing difficulties. Scorching temperatures are often followed by flash flooding.
A four-day yellow heat alert was issued by UK Health Security Agency and the Met Office this week, with temperatures peaking at 30.3C at Heathrow on Wednesday – the highest temperature since last September.
However, temperatures are forecast to fall to 22C in London on Friday but rise to 25C with a day of sunshine on Saturday.
At Glastonbury, which opened last night with a drone show, revellers were told to expect showers but forecasters ruled out either a downpour or a weekend heatwave.
On average, temperatures at the festival are expected to be about 5C lower than the capital.
The festival at Worthy Farm in Somerset gets going in earnest tomorrow, with Dua Lipa headlining the Pyramid Stage. She will be followed by Coldplay on Saturday and SZA on Sunday. Shania Twain is due to appear in the “legends” slot on Sunday afternoon.
Operation Helios will involve more than 80 participants from the emergency services, local government, public health, environment agencies, transport, utilities and business.
The exercise is one of the recommendations from the London Climate Resilience Review, commissioned by Mayor Sadiq Khan to examine London’s preparedness for extreme weather.
It will help to inform the development of a new pan-London extreme heat plan. Scientists have warned that the capital could face prolonged heatwaves by 2027.
Attendees will need to consider the impacts of the updates on individuals, communities and services and respond accordingly.
Two years ago, 19 homes were destroyed in the east London village of Wennington, near Rainham, after wildfires spread. The following month the fire brigade was “stretched to the limit” by 200 wildfires over a weekend.
Mr Khan said: “Over the past few years we have seen the damaging and dangerous effects of extreme heat and climate change in London, and Operation Helios provides a vital opportunity to bring partners together and plan how we can manage these threats in the future.
“We were the first global city to declare a climate emergency in 2018 and have been working tirelessly to combat the impacts of climate change ever since.
“London needs to become a climate resilient city and testing and improving London’s response to extreme heat is essential as we work to build a fairer, greener London for everyone.”
London Fire Brigade assistant commissioner Thomas Goodall said: “As the weather is becoming increasingly unpredictable, we must learn how to react to ever-more challenging incidents.”
