ROME - Swathes of southern Europe sweltered Saturday in a heat wave that has claimed several lives, cost billions in crop damage and is, scientists warned, a foretaste of worse to follow in coming decades.

At least five deaths in Italy and Romania have been attributed to the extreme conditions since the heatwave set in around the start of August.

Unusually high, sometimes unprecedented temperatures, are being recorded across an area spanning much of the Iberian peninsula (Spain and Portugal), southern France, Italy, the Balkans and Hungary.

Thermometer mercury has regularly risen above 40 C across the affected areas, exacerbating the impact of an extended drought and the lingering impact of a July heatwave which sparked wildfires that claimed 60 lives in Portugal.

Hospital admissions have spiked 15 to 20 percent in Italy, where at least three people have died.

Italians longing for the beach have dubbed the hot spell "Lucifero", or Lucifer, after the biblical archangel said to have been condemned forever to the flames of hell.

In Romania, two deaths were linked to the weather, including a farmworker who collapsed after working in fields in the heat at Mogosesti in the northeast of the country.

In Italy, humidity and other factors are making it feel much hotter with the so-called perceived temperature in Campania, the region around Naples, estimated at a broiling 55 C on Friday.

Hospital admissions are running 15 to 20 percent above seasonal norms and food producers are forecast to suffer billions of euros in losses as a result of reduced crop yields.

Italian wine and olive production is tipped to fall 15 and 30 percent respectively this year.

In Rome, tourists have been risking recently-introduced fines for splashing in the Eternal City's fountains to cool off.

But there has yet to be any sign of visitors to southern Europe's summer hot spots being deterred by the rising trend in temperatures.

Tourists were lining up once more Saturday outside Florence's Uffizi museum, which was forced to close Friday after its air conditioning broke down because of a lack of water from the dried up River Arno.

Health authorities in France have warned citizens to be particularly aware of the risks faced by the sick and the elderly.

The country is still haunted by memories of a 2003 heat wave which resulted in an estimated 15,000 avoidable deaths among pensioners, some of whom had been left on their own by holiday-making relatives.

Scientists meanwhile warned that deaths due to extreme weather in Europe could increase from an estimated 3,000 per year recently to 152,000 by the end of this century - if global warming is not reined in.

Southern Europe will suffer most and heat waves would account for 99 percent of the deaths, according to research conducted for the European Commission and published in The Lancet Planetary Health.

Scientists warned last week that large parts of South Asia, home to one-fifth of the world's population, could become unbearably hot by the end of this century.

Agence France-presse