Poland faces 'tropical nights' as temperatures climb toward 39C

Poland is bracing for an intense heat wave this weekend, with forecasters warning of "tropical nights" and temperatures approaching 39 degrees Celsius (102.2 degrees Fahrenheit), local media reported on Friday.

Nighttime temperatures are expected to remain above 20C (68F) across many parts of the country, preventing people from recovering from daytime heat and increasing health risks, according to the Polish state news agency PAP.

"It's not only about the weather during the day, but also at night," meteorologist Michal Brennek of the Polish Academy of Sciences said.

He warned that continuous exposure to high temperatures around the clock could be "extremely dangerous."

The hottest conditions are forecast for western and southwestern Poland on Sunday, where temperatures could climb to 39C, nearing national records.

Brennek said cities are likely to experience the most severe conditions because dense urban development traps heat, while asphalt and concrete continue to release warmth after sunset.

"In larger towns there is a concrete landscape, limited access to greenery and shelter from the sun. This is a recipe for very heavy, dangerous heat," he said.

He added that the perceived temperature in urban areas could exceed 40C (104F), warning that Polish cities were not designed to cope with such extreme heat.

The latest heat wave comes as much of Europe experiences its second major spell of extreme temperatures this year, with record or near-record heat reported in France, Spain, Portugal, and the UK.