Europeans suffering Sahara-like weather over the past week "could see a drop in temperatures from August 15", said Dominique Escale, meteorologist for France's national weather service Meteo France.

From Manchester to Madrid, temperatures have regularly risen to the uncomfortable upper-30s Celsius throughout the week, with several cities topping 40 degrees Celsius (104 degrees Fahrenheit).

An elderly woman on Saturday became the 19th victim of the heat wave stifling Spain.

The woman, 75, died in the hospital in the southern province of Andalucia where she had been admitted on Thursday.

The blistering heat coupled with severe drought has helped whip up forest fires in several countries, with weary firefighters struggling to rein in blazes in Portugal, Italy and France.

Altogether, 20 people have been killed in the fires ravaging France and Portugal, bringing the total summer death toll to 39 in the space of two weeks.

In France, police arrested five people including a 17-year-old girl in connection with a blaze which destroyed three hectares of brush and trees on the outskirts of the southern riviera resort of Nice overnight.

Scores of residents and tourists were evacuated from their hillside villas around the observatory to the east of the town, said firefighters who brought the blaze under control some three hours after it was reported.

But two more fires had already started on Saturday, some 30 kilometresmiles) northeast of Nice, where 1,600 hectares of brush and forest have already been consumed by the flames.

Firefighters in Portugal said on Saturday they were now in control of the fires which have killed 15 people since the end of July.

A spokesman said the firefighters were now tackling three medium-sized blazes, burning near the central city of Leiria and in the southern districts of Portalegre and Faro.

More than 2,000 Portuguese firefighters and 800 soldiers are involved in the firefighting operation or monitoring forests for signs of new flare-ups.

Lisbon estimates the damage caused by the fires so far at one billion euros (1.1 billion dollars).

More than 10 wildfires were meanwhile still raging in Italy, where some 300 holidaymakers were evacuated overnight from an area close to the southern city of Naples. Other fires were still raging elsewhere in the Naples region, as well as the central province of Tuscany.

Further east in Croatia on Saturday, 130 firefighters were parachuted in from helicopters to tackle the blaze raging in the Paklenica national park, in the country's mountainous centre, news agency Hina reported.

The task facing them is doubly hazardous: the near-inaccessible region is one of the areas of the country that has still not been swept for landmines, scattered liberally around the area during the 1991-1995 war in Croatia.

The government of Slovakia, meanwhile, has declared the country's forests off limits to the public, with the exception of marked tourist paths.

The summer blazes have destroyed around 175,000 hectares (430,000 acres) of pinewood and brush across the continent, most of it in Portugal, where authorities said the damage totalled 925 million euros (1.05 billion dollars).

Europe's farmers are also suffering: producers in parts of the German state of Brandenburg said the heat could destroy up to 80 percent of their crops, while in France, about one million chickens have died this week.

Rising water temperatures forced German authorities to close a nuclear power plant and reduce output at two others.

In Romania, port authorities said the wrecks of two Nazi ships that sank in the Danube during World War II but recently resurfaced due to low water levels could block traffic on the river, one of Europe's longest waterways.

The heatwave was caused by an anticyclone which has anchored itself firmly over the west European land mass, holding off rain-bearing depressions over the Atlantic and funnelling hot air north from Africa.

Though there was no clear evidence putting the blame on global warming and greenhouse gas production, scientists at the World Meteorological Office point out that the world's 10 hottest recorded years have all taken place since 1987.

"The evidence seems to point to human factors -- that's basically the concentration of greenhouse gases," said Rajendra Pachauri, the head of a United Nations scientific panel on climate change.

"The danger is that these extreme events will increase in the future. So this is a warning of sorts of what we're likely to get in the future," Pachauri added.

SPACE.WIRE