Italy on red alert, Hungary turns off the lights as Europe's heatwave takes toll 

Italy took the unprecedented step of placing all its major cities on the highest level of health alert due to high temperatures on Thursday while Hungary turned off the lights at some of its best-known buildings to save energy as a heatwave maintained its grip on large parts of Europe.

Europe, the world's fastest-warming continent, has been ravaged by record-breaking heat and destructive wildfires this summer, with France and Spain particularly hard hit in recent weeks.

The focus of the heatwave has since moved further east, with temperatures in Austria hitting successive national records this week, peaking at 41.2 degrees Celsius on Wednesday.

Italy is accustomed to hot summers, but the red alert issued by the Health Ministry stretches from Palermo on the southern island of Sicily to Bolzano in the mountainous north. Such a warning indicates a potential health emergency with prolonged high temperatures posing a serious health risk to the entire population.

In the northwestern city of Genoa, people aged 65 and over can escape the heat by visiting museums and libraries free of charge during the hottest hours of the day this month. Rome extended its scheme of offering free screenings in air-conditioned cinemas by 10 days to August 14.

With rivers at historic lows, the region of Piedmont, centred on the city of Turin, declared a state of emergency this week for drought and the risk of wildfire.

LOW WATER LEVELS CAUSE PROBLEMS

Hungary has switched off decorative and non-essential lighting at all state institutions, including its Parliament, most of the Buda Castle and Chain Bridge, at night to save energy.

Record-low water levels on the Danube have forced the country to largely shut down its sole nuclear plant, which uses the river for cooling, stretching power supply capacity to its limits.

Romania was preparing to sink four rock-filled barges into the Danube to divert water to its only working reactor and buy a few more days of operation.

The authorities in the capital Bucharest have dimmed the intensity of street lights by a third and switched off lighting at night at landmark buildings and museums to save power.

Low water levels are causing problems for shipping on the Rhine in Germany, where many vessels can sail only part-loaded, raising freight costs. The river is an important shipping route for commodities such as grains, minerals, coal and oil products.

DODGING THE HEAT IN A COOL CAVE

In Bosnia, tourists have taken shelter in the constantly cool temperatures of the UNESCO-listed Vjetrenica cave to escape outside temperatures of 40 C.

Vjetrenica, which means wind cave, is located in the south of Bosnia and Herzegovina, about 25 km north of the Adriatic town of Dubrovnik, where cruise liners arrive daily with thousands of visitors.

Numbers allowed to visit the cave are limited because of the sensitivity of the environment. Its constant 11 C temperature year-round has made it a refuge for biodiversity as well as for humans.