UK and Europe heatwave news: live updates

“I’m not worried about myself in this heat,” said Ms. Solomon, who is originally from Eritrea. “But I worry about my children.”

She said her apartment was getting hotter, and despite being advised to keep her children, ages 6-10, home from school, she decided to send them to her because she thought it might be cooler there.

Schools, most of which were in the last week of school before the summer holidays, were doing their best to keep children cool, especially in old buildings ill-equipped for the high temperatures. In one elementary school off Portobello Road, staff set up a wading pool, and children could be heard laughing in the street.

“Especially at night, in the summer it is very hot in my apartment,” Ms. Solomon said, adding that she was worried it would become unbearable on Monday night.

Ms. Al-Amin said Muslim women, who wore traditional dress and headscarves, didn’t mind the weather outside in their light cotton clothes, but were concerned about taking the bus.

“At this time, the situation is very difficult,” she said. “There is not enough air.”

In Hyde Park, a bunch of sunbathers braved the noon heat and laid blankets on the clear lawn. Steps away, would-be swimmers were turned away from the Serpentine Lido, where a sign indicating the facility was at capacity. Among them were Lalo Laredo, 19, and Rachel Trippier, 22, who were disappointed with their removal but noticed that the warm water, whose temperature was 26°C (78.8°F), might actually make them feel worse.

“London is not really good for days like this,” Ms Laredo said, lamenting the lack of places to cool off in the sweltering temperatures.

Ms Trippier added that she was concerned about the new reality of rising temperature extremes.

Mrs. Laredo agreed. “It’s always in the back of our minds,” she said. “It’s frustrating that people still deny it.”

Across central London, the neighborhood near St Paul’s Cathedral was bustling with activity at lunchtime, despite the heat. Few runners avoided traffic and pedestrians in the hot sun. Tourists stood in the shadow of the cathedral, reviewing maps on their phones. The office staff were in their suit jackets outside despite the heat and carrying ready-to-eat food.

The bars used the scorching sun to their advantage. “Ice Ice Baby!” It was written on a sign outside one pub, Paternoster. “Refreshing Peach Iced Tea or Iced Coffee!”

On a working day, there are usually at least 80 people in the pub for lunch. But on Monday, when many workers were encouraged to work from home, there were five.

“It usually gets busier than this,” said Sam Jordan, a 22-year-old bartender. “I think a lot of office workers work from home.”

In neighboring Paternoster Square, about 36 people sat on lawn chairs or at picnic tables, some in the shade, eating lunch and watching a big screen set up weeks earlier for the audience to watch Wimbledon. On Monday, the audience watched a presentation on politics and the upcoming battle to choose a new prime minister.

Marilyn Tan, who was wearing a protective umbrella, said she had just got off a plane from Singapore, where the weather was a little cooler than London.

Ms. Tan, 57, said: “It had no effect on me. I’m fine. I haven’t even tied my hair back.”