A visitor poses for a photo at the Old Town in Warsaw, Poland, on July 1, 2025. Poland's meteorological authorities have issued heat warnings for much of the country this week. (Photo by Jaap Arriens/Xinhua)

A child plays with floating soap bubbles at the Royal Castle Square in Warsaw, Poland, on July 1, 2025. Poland's meteorological authorities have issued heat warnings for much of the country this week. (Photo by Jaap Arriens/Xinhua)

Children play with floating soap bubbles at the Royal Castle Square in Warsaw, Poland, on July 1, 2025. Poland's meteorological authorities have issued heat warnings for much of the country this week. (Photo by Jaap Arriens/Xinhua)

A waiter serves food to customers at an outdoor restaurant in the Old Town of Warsaw, Poland, on July 1, 2025. Poland's meteorological authorities have issued heat warnings for much of the country this week. (Photo by Jaap Arriens/Xinhua)

A child plays with floating soap bubbles at the Royal Castle Square in Warsaw, Poland on July 1, 2025. Poland's meteorological authorities have issued heat warnings for much of the country this week. (Photo by Jaap Arriens/Xinhua)

A child plays with floating soap bubbles at the Royal Castle Square in Warsaw, Poland on July 1, 2025. Poland's meteorological authorities have issued heat warnings for much of the country this week. (Photo by Jaap Arriens/Xinhua)

People relax by a shallow pool at a public park in Warsaw, Poland, on July 1, 2025. Poland's meteorological authorities have issued heat warnings for much of the country this week. (Photo by Jaap Arriens/Xinhua)

People relax on deck chairs at a green area in downtown Warsaw, Poland, on July 1, 2025. Poland's meteorological authorities have issued heat warnings for much of the country this week. (Photo by Jaap Arriens/Xinhua)

A child plays with floating soap bubbles at the Royal Castle Square in Warsaw, Poland, on July 1, 2025. Poland's meteorological authorities have issued heat warnings for much of the country this week. (Photo by Jaap Arriens/Xinhua)

A child plays with floating soap bubbles at the Royal Castle Square in Warsaw, Poland, on July 1, 2025. Poland's meteorological authorities have issued heat warnings for much of the country this week. (Photo by Jaap Arriens/Xinhua)