Nearly 100 years ago, in a celebrated essay, the German social scientist Werner Sombart asked: "Why is there no socialism in the United States?" His answers, including the open western frontier and unusually high social mobility, formed much of the groundwork for the doctrine of American exceptionalism, which roughly states that the US differs from every other western country in almost every way.
But in this summer's heatwave, a countervailing doctrine of European exceptionalism might be required to explain an estimated death toll of at least 10,000 in France alone. After all, it gets pretty hot in America. From 1971 to 2000, the US as a whole has been just over four degrees Celsius hotter than the UK in June, July and August. Its warmest parts, such as Phoenix, Arizona, average nearly 35 degrees Celsius in July, compared with less than 22 degrees in south-east England.
The American answer is air-conditioning. And as Americans sit in their climate-controlled living rooms and offices and read about Europeans sweltering in their homes, they probably ask: "Why is there so little air-conditioning in Europe?"
More than three-quarters of American homes have at least one air-conditioner, more than 90 per cent in some southern states. The percentage of British homes with air-conditioners is "negligible", according to Richard Rooley, president of the American Society of Heating, Refrigerating and Air-Conditioning Engineers, and these are limited to high-rental apartment blocks in central London. And in France, not even one in 20 homes has an air- conditioner. European air-conditioning is still concentrated in the south: three-quarters of the 2.5 million air-conditioners sold in the European Union in 2000 were in Spain, Italy and Greece.
If Europeans joined the Americans in embracing air-conditioning, however, the implications would be serious. Air-conditioners are energy guzzlers: in the home, they consume between four and 20 times as much energy as a powerful electric fan, and cars equipped with air-conditioners burn more fuel. Tom Devleesschauwer, of the consulting firm Global Insight, says manufacturers have kept that quiet because of the substantial premium customers pay for air-conditioned vehicles.
Moreover, according to a paper by Ian Maclaine-Cross of the University of New South Wales in Australia, leaks from the refrigerants used in air-conditioning systems - hydrofluorocarbons (HFCs), which replaced the ozone-depleting chlorofluorocarbons after the latter were banned in 1995 - increase global-warming emissions by about 15 per cent.
In August, the European Commission proposed a ban on HFCs used in car air-conditioners by 2013, as part of a plan to help the EU meet targets set by the Kyoto Protocol. According to Devleesschauwer, if the ban came into effect, every car air- conditioning unit in Europe would have to be replaced and all current manufacturing infrastructure would become obsolete.
A hotter climate cannot entirely excuse Americans from this environmental recklessness. Even people in colder states tend to own air-conditioners for whatever summer days require it. A/C, as Americans call it, has as much to do with a culture of comfort as with comparative climates.
Air-conditioning was invented in 1902 by Willis Haviland Carrier, a printing plant worker who devised a system to maintain a steady temperature in the plant so that the paper's dimensions would not fluctuate and cause the coloured inks to misalign. For the next two decades, air-conditioning was used exclusively for industrial purposes. Stuart H Cramer was the first to use the term, in a patent application for a device that would "condition" the air to stop yarn from getting fuzzy and difficult to sew. Then, in 1924, air-conditioning was used for comfort purposes, when the J L Hudson department store in Detroit, Michigan, installed three large units to lure summer shoppers into the cool atmosphere.
Shortly afterwards, New York's Rivoli Theatre began to advertise its "cool comfort" in the summer and became the talk of the town. In 1928, the Carrier Engineering Company (founded by the inventor) introduced the first home air-conditioner, the Weathermaker. But the Great Depression deflated household budgets sufficiently to prevent the technology from catching on.
It was in the postwar boom that air-conditioning became a staple of American life. As the nation suburbanised in the 1950s, the air-conditioner became emblematic of the suburban home, especially in the warmer states such as California which received most of the migration.
As the American dream of a two-storey house in a cul-de-sac, with a garden and a barbecue, became a reality for millions, home took on a new role. "[Suburbanites] thought of the home as a refuge from all kinds of unpleasant outside forces, like racial issues and the big bad city versus the pleasant suburban countryside," says Marsha Ackermann, author of Cool Comfort: America's romance with air-conditioning. "Escape from heat became part of this idea that the home was safe from these nasty forces which would weaken the US and make it vulnerable to conquest by its enemies." Whatever the weather outside, Americans want to proclaim their ability to conquer it. To many Europeans, American homes and offices seem too cold in summer, just as they seem too hot in winter.
A 1959 Carrier air-conditioner advertisement shows how control over temperature became a metaphor for control over life - with abundant sexual overtones for those who want to see them. "It's the biggest 112 square inches in air-conditioning," the advertisement proclaimed. "A revolutionary panel that gives new mastery of indoor climate . . . There's something masterful about flipping switches and turning knobs, and then feeling and seeing how your air-conditioning responds."
Some purists complain that air-conditioning destroyed traditional southern architecture (eliminating, for example, long central halls) and lifestyle (sitting on front porches). But it replaced them with the cookie-cutter houses that would become the signature images of Americana. The centrality of air-conditioning to suburban iconography helped to populate much of the US: southern California, Florida and, more recently, "sun belt" states such as Arizona. "In their modern form, their size and expanse, ability to attract industry, [those areas] wouldn't exist without air-conditioning," Ackermann says.
It is the American cultural construct of air-conditioning, she suggests, that makes it anathema to a British sensibility. Unlike Americans, who equate comfort with control, Britons take "a certain pride in not complaining, the stiff upper lip", she says. "There's a general European attitude that Americans are pampered cry-babies, and air-conditioning is part of that."
Air-conditioning does offer economic benefits - at least according to its supporters. Richard Rooley claims a proper air-conditioning system increases worker productivity in warm weather by more than 20 per cent. Those benefits, however, perhaps appeal more to Americans, who are geared to squeezing every last ounce of work from their labour force.
Yet Europeans are moving towards their own air-conditioned Utopia all the same. Five years ago, according to Devleesschauwer, 55 per cent of cars in western Europe had air-conditioning; the figure for this year is expected to be 82 per cent.
And, he predicts, the more Europeans get used to cooling off on the road, the more dismayed they will feel when they get home to a virtual sauna. Moreover, globalisation is making it easier for them to take the plunge - many Asian manufacturers have slashed prices on home units, turning what was a luxury item into an affordable household appliance. "If we have two or three more summers like this, there may well be changes," says Rooley.
Ackermann believes Americans have become too reliant on air-conditioning and rarely consider the alternative of, say, opening a window to a cooling breeze. "People don't think about when they need to use air-conditioning and when they don't," she says. "They don't think about other values in their lives."
She suggests that Britons could set an example, using air-conditioning as a tool rather than a dominating technology. If they and other Europeans fail to do so, the prospects for the planet look gloomy, as greenhouse gas emissions alter the climate and, in an effort to cool down, we contribute yet further to global warming.