But it has also alarmed farmers who are seeing crops shrivel under the sun and governments who are concerned about dwindling water supplies and a rash of forest fires.

The Swiss Alps have cracked under the heat, forcing the evacuation of hikers. And London's transit authorities have promised a six-figure reward for anyone who can work out some way to air-condition the sweltering Underground subway network.

Even a storm front sweeping across Britain and France has brought little relief.

The dark clouds have caused at least five deaths in France but brought little of the much-needed rain and only a brief dip in temperatures that will return to around 30 degrees Celsius (86 degrees Fahrenheit) by the weekend.

In Paris, tourists could be seen standing in long lines for ice cream or sunbathing at the foot of the Eiffel Tower. Many residents have abandoned the city for their annual month-long vacation on the Riviera, where the water temperature was a bath-like 26 degrees Celsius (79 degrees Fahrenheit).

On Wednesday, French authorities issued a weather warning for several regions after a night of storms that killed five people, including a two-year-old girl and two Dutch tourists -- a 39-year-old man and a 10-year-old girl -- all hit by falling trees at camp sites, police said.

Seventy other people were hurt in the tempests, which were forecast to continue to Thursday.

In Switzerland, a 38-year-old woman was killed when a caravan overturned onto her in a storm in the northeastern region of Linth, local police said. The violent weather also damaged houses and cars in the region.

In Linth and in Zurich, several roads and railway lines were blocked by falling trees.

Britain recorded its hottest day in 14 years on Tuesday when the mercury in Wisley, a town south of London, reached 33.5 degress Celsius (92.3 degrees Fahrenheit).

The Sun tabloid newspaper claimed sales of barbecues for a major retailer had jumped 90 percent as people took days off work to soak up the unusually good weather before days of lower temperatures and showers take over.

London mayor Ken Livingstone on Tuesday offered 100,000 poundseuros, 160,000 dollars) to anyone who can "come up with a scheme that is workable that we can use to introduce some form of air conditioning on the deep level lines" of the city's Underground.

Low water levels in the main rivers of Europe have sparked worries, too.

The Danube, Romanian authorities said, was at its lowest point for the month of July since 1953, causing several barges to run aground. Lack of water also meant hydroelectric turbines were pumping out 15 percent less electricity, driving up the price for Romania's residents.

The Czech Republic said that the Elbe river had dropped drastically, virtually paralysing water traffic on the Czech-German border.

Italy's Po river, which irrigates the northern half of the country, has gone down to record lows, resulting in water rationing for some regions. German officials ordered similar restrictions due to the low level of the Rhine.

"Usually the low-water period for the Rhine starts in August or September. This year it started in February," said Silke Rademacher, an expert at the Hydrology Office in the western German city of Koblenz.

Across much of Europe, the scorching heat has aggravated a months-long drought, killing off crops and setting conditions for forest fires in Italy and France.

Hungary's prime minister, Peter Medgyessy, said 20 percent of this year's harvest had been wiped by what has become the worst drought since 1950. In neighbouring Slovenia, the parliament delayed its summer recess to pass a bill to compensate the country's farmers for their as-yet-unquantified losses.

In the Swiss Alps, chunks of glaciers broke off in the heat this week, causing landslides and forcing authorities to evacuate climbers and hikers. June was reported to have been the hottest month on record in Switzerland since weather observations began in 1864.

The unseasonal weather has also made the annual Tour de France bike race an ordeal for the cyclists.

On Tuesday, several slipped on tarmac that had turned gooey in the heat, and Joseba Beloki, a Spanish rider who had been seen as one of the main threats to four-time champion Lance Armstrong, broke a leg, wrist and elbow when his tyre blew on a descent near the town of Gap.

TERRA.WIRE