There are few more unmistakable signs that summer has arrived in Britain than hearing the chimes of an icecream van from the street.
But Londoners could soon find it harder to track down soft-serve on a hot day, because of fears that pollutants from the trucks' diesel engines may be endangering lives.
Councils in the city are threatening to clamp down on icecream trucks that roam their streets if they do not become more environmentally friendly.
"No one wants a side order of asthma with their icecream," Caroline Russell, a Green Party member of the London Assembly, said.
The issue of toxic air has plagued London for years, with more than 9000 Londoners estimated to die prematurely each year from long-term exposure to pollution.
Environmental issues have been at the forefront of the Britain's political agenda for weeks.
Last month, officials introduced a charge on older, polluting vehicles in central London. Activists took over major London landmarks for weeks as part of a campaign to demand government action on climate change. And last week, the Parliament declared a climate emergency, following in the steps of Scotland and Wales and major British cities.
Although the musical chimes of icecream vans have been named one of Britons' happiest childhood memories, vendors' eco-credentials have been unable to escape scrutiny.
"The local authorities are cracking down on diesel vehicles driving around, pitching up and running their engine for hours, creating very serious health impacts," said Russell.
Icecream truck owners said that Britons' penchant for soft serve icecream is one of the drivers of the diesel pollution problem. The trucks' freezers can operate with the engine turned off, but the machines that pump out soft-serve icecreams such as Mr Whippy need engine power to run.
"We have got to be conscious of the impact of diesel," Amy Rudgley, 25, who worked in icecream vans in London for eight years before starting her own business, Fat Cows Ice Cream, said.
"But it has to be seen as a bigger picture than just icecream vans," she added.
As he sat in his truck on a central London street on Friday, taking a break from serving hungry tourists and Londoners who had been enjoying some fleeting sunshine, Ndue Meli, 45, echoed the complaint. His truck, which cost him 100,000 pounds, meets the latest European Union standard on emissions, he said.
"My van does not burn a lot of fuel," Meli said. "I see black cabs, tourist buses and coaches which are all pumping out fuel. But the councils are putting everybody in the same boat."
As London explores ways to reduce air pollution caused by all diesel vehicles, one solution offered is to install electric power points in parks and popular spots, which would allow icecream trucks to turn off their engines and run their machines on electricity instead.
That strategy is favoured by Britain's icecream industry trade body, the Ice Cream Alliance, over an outright ban.
"There is a danger of icecream vans disappearing from our streets altogether," Zelica Carr, chief executive of the Ice Cream Alliance, said in a statement.
The prospect of summers without icecream vans had Londoners expressing dismay on Twitter this past week.
Meral Duzgun shared her disappointment, using the hashtag "HandsOffMy99Flake" to refer to a British favourite, a soft serve ice cream cone topped with a stick of chocolate.
Another Twitter user wrote: "Some councils have no sense of fun."
Eager to save the industry from extinction, one icecream truck manufacturer, Whitby Morrison, says it's working to develop a fully electric system by the end of the year.
"The icecream van is a British tradition," said Ed Whitby, the company's operations director. "It is an icon that we have all grown up with. I would like to see it be a part of everybody's life for generations to come."
Lambeth and Islington, two central London boroughs, have already installed power points in local parks. Two other councils, Richmond and Tower Hamlets, said they were considering something similar.
In the meantime, Hammersmith and Fulham Council in West London, which is trying to become the "greenest" borough in Britain, shared a different solution.
An unlicensed icecream vendor who kept a truck's diesel engine running all day outside a subway stop in the area was recently persuaded by the council to swap his truck for an electric tricycle.
Whether hearing the sounds of an icecream tricycle as it makes its way down the street would conjure up the same nostalgia and childhood memories for Britons remains to be seen.
c.2019 New York Times News Service
Written by: Anna Schaverien
© 2019 THE NEW YORK TIMES