Londoners take the heat in stride.

LONDON — By Monday afternoon, temperatures had reached 34 degrees Celsius (94 Fahrenheit) in north London, but residents were anxiously looking ahead to Tuesday, when it was forecast to be even hotter.

Mona Suleiman, 45, and her friend Zaina Al Amin, 40, were waiting for a bus as the afternoon grew warmer.

“I am not worried about myself in this heat,” said Ms. Suleiman, who is originally from Eritrea. “But I am worried about my children.”

Her apartment gets too hot, she said, and despite being advised to keep her children, ages 6 and 10, home from school, she decided to send them in because she thought it might be cooler there.

Schools, most of which are in their final week of classes before a summer break, were doing their best to keep children cool, especially in older buildings ill-equipped for the high temperatures. At one elementary school off Portobello Road, staff had set up a wading pool, and the children could be heard splashing and laughing up the street.

“Especially at night, in the summer in my flat it’s already too hot,” Ms. Suleiman said, adding that she was worried that it would become unbearable on Monday night.

Ms. Al Amin said the women, who are both Muslim and wore traditional dress and headscarves, didn’t mind the weather outside in their lightweight cotton clothing, but were worried about boarding the bus.

“At this time, it’s too difficult,” she said. “There’s not enough air.”

In Hyde Park, a handful of sunbathers braved the afternoon heat and lay blankets on the visibly parched grass. Steps away, prospective swimmers were being turned away from the Serpentine Lido, where a sign signaled the facility was at capacity. Among them were Lalou Laredo, 19, and Rachel Trippier, 22, who were disappointed to be turned away but remarked that the warm water, which was 26 degrees Celsius (78.8 Fahrenheit), might actually make them feel worse.

“London really isn’t good for days like this,” Ms. Laredo said, lamenting the lack of places to cool down in the extreme heat.

Ms. Trippier added that she was worried about the new reality of increasingly extreme temperatures.

Ms. 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 bustled with activity at lunchtime, despite the heat. A few joggers dodged both traffic and pedestrians in the blazing sun. Tourists stood in the shade of the cathedral, consulting maps on their phones. Office workers wore suit jackets outside despite the heat, carrying takeaway food.

Pubs used the blazing sun to their advantage. “Ice, Ice, baby!” was scrawled on a signboard outside one pub, The Paternoster. “Refreshing peach ice tea or ice-cold coffee!”

On a workday, the pub would normally have at least 80 people at lunch. But on Monday, when many workers had been encouraged to work from home, there were five.

“It is usually busier than this,” said Sam Jordan, 22, a bartender. “I think a lot of office workers are working from home.”

In nearby Paternoster Square, about three dozen people sat in lawn chairs or at picnic tables, some in the shade, eating lunch and watching a large screen that had been erected weeks ago for the public to watch Wimbledon. On Monday, the crowd watched a show about politics and the upcoming battle to select a new prime minister.

Marilyn Tan, wielding a protective umbrella, said she had just gotten off a plane from Singapore, where the weather was slightly cooler than London.

“This has had no effect on me,” said Ms. Tan, 57. “I am fine. I didn’t even tie my hair back.”