Volkswacht Bodensee - French grape-pickers wilt as 'heat dome' temperatures top 40C

In Saint-Quentin-de-Baron in the Bordeaux region of southwest France, local winemakers have adapted the picking routines to take into account some of the hottest temperatures on record for this time of year.

Sebastien Jacquey, director of the Chateau de Sours, told AFP that shifts had been reduced to six hours a day, instead of eight, and that teams were starting at 7 am to avoid the suffocating heat and humidity of the wind-free afternoons.

Teams armed with secateurs and boxes were reminded of safety routines as they headed out Tuesday to the neat rows of vines, which are owned by Chinese billionaire Jack Ma.

"Remember to take a break at the end of a line, keep yourself hydrated, protect yourself with hats and sun cream, but also let someone know if you don't feel well," Jacquey said.

Despite the guidelines and drinking regularly, Aurore Bernard, a 35-year-old picker doing her first harvest with her mother, said she had fallen ill on Monday.

"I felt my heart start to beat rapidly, I felt dizzy, heard noises and felt very, very cold," she told AFP.

Fellow worker Anthony Chappel, 42, said the key was using the shade of the vines to work in.

"The more suffocating it is, the more you get hot and the more dangerous it is," he said as he headed out with the forecast for a peak of 34C in the afternoon.

"I don't think there'll be any wind today. It'll be torrid."

- 'Intense' heatwave -

French authorities have placed roughly half of the 96 departments on the mainland on the second-highest heat warning level, with four areas around the southern Rhone valley placed in the maximum red category.

Temperatures are expected to peak there at 40-42C on Tuesday (104-107F).

The country as a whole experienced its hottest day ever recorded after August 15 on Monday when the national average was clocked at 26.63C, according to the national weather service Meteo France.

It has called the current heatwave "intense and long-lasting" and "particularly late in the season", with a period of stable high pressure creating a "heat dome" over the country with little wind.

In the sweltering southeastern city of Lyon, 26-year-old PR worker Emma Solet told AFP it was 29C in her apartment at 6:30 am and she had bought herself an air-conditioner for the first time.

"It's not good for the planet, I know, and it actually didn't work," she explained. "I took it back to the shop. The heat is in the walls."

The heatwave is also affecting the normally cool Alps where mountaineers preparing to tackle Mont Blanc have been urged by local authorities to delay scaling the summit of western Europe's highest mountain.

Officials in the Haute-Savoie region, which includes the French side of Mont Blanc, said there were higher-than-usual risks of rockfalls on the regular routes up the mountain, as well as new crevices opening up on its glaciers.

Swiss weather authorities said Monday that a new record had been set for the altitude of the so-called zero-degree line in the Alps -- the height at which the temperature dips below zero degrees Celsius.

It was clocked overnight from Sunday to Monday at 5,298 metres, "which constitutes a record since monitoring began in 1954", MeteoSwiss said.

- 'Not such a bad thing' -

For the wine harvest in France, the heatwave could bring some cheer to vintners, if not their workers.

The Bordeaux region has been badly hit by mildew this year and the burst of heat at the end of ripening process could be positive.

"It stops rot and dries out any illnesses, so it's not such a bad thing," said Stephane Gabard, head of the Bordeaux et Bordeaux Superieur winemakers' group.

The timing of grape harvesting varies around the country depending on the type of grapes, local weather conditions and the flavours and alcohol content desired by the wine maker, with southern vineyards usually kicking off the season in August.

The start of the picking season, which generally ends in October, has been advancing year-on-year due to climate change.

J.Horn--BTB