The government said Monday it was difficult to determine if the deaths were weather-related, because it is often not clear whether patients admitted to hospitals suffer only from heat or from other ailments.
Patrick Pelloux, the head of France's emergency hospital physicians' association, insisted scores of deaths were going uncounted in the Paris region and accused the government of failing to deal with a silent health crisis.
"They dare to talk about ... natural deaths. I absolutely do not agree with that," Pelloux told TF1 television late Sunday.
The government acknowledged an increase in the number of elderly being treated at hospitals, but said it was unclear if the heat was to blame.
"People don't come in with 'dying of heat' on their foreheads," said Stephane Grossier, of the Health Ministry. "Things are not as simple as they seem."
Still, funeral directors say demands for their services has risen sharply since the heat wave took hold. Les Pompes funebres generales, France's largest undertaker, said it has handled 50 percent more bodies in Paris, a company spokesman said. He noted the increase was "tied to the heat wave."
Five people between the ages of 89 and 96 died in a retirement home over the weekend in the Essonne, a region south of Paris, the home's director told The Associated Press.
Elsewhere in Europe, authorities counted at least 45 heat-related deaths, the latest occurring in Spain, where five people died Monday while fleeing a forest fire.
The victims, apparently members of one family, left home in the northeastern town of Sant Llorenc Savall and died of smoke inhalation, officials said. Most other Spanish victims were elderly and suffered from chronic lung and heart diseases, officials said.
Temperatures were expected to surge to 109.4 in some areas of southern Spain this week before dropping off, the National Weather Center said.
A record high for nighttime temperatures in Paris was set overnight Sunday to Monday, when the thermometer hit 77.9, according to Meteo France, the national weather service. The previous record was 75.2, set in 1976.
Because of high pollution caused by the heat, Paris police urged motorists not to use their cars Monday and reduced speed limits.
Not even the Nordic countries have been spared. Temperatures in Denmark reached 89.6 over the weekend.
In Roskilde, west of the capital, Copenhagen, taxi driver Per Bjoerneboe got around his employer's ban on shorts by wearing a skirt to work.
"To me it's an insult that I'm not allowed to wear shorts," he was quoted as saying in the newspaper Dagbladet Roskilde. "Some of my customers think it's very funny and laugh their heads off."
Italian firefighters put out a blaze Monday that burned for several hours in the hills above Positano and Maiori, two popular tourist towns on Italy's Amalfi Coast near Naples. Authorities suspect people are taking advantage of the searing heat and rain-parched earth to set fires to clear land for farming or development.
In the northern German city of Kiel, garbage collectors began work at 5:30 a.m. instead of 7 a.m. to make removing the city's fast-rotting rubbish more tolerable. The German arm of Italian candy maker Ferrero said it had suspended deliveries of chocolate eggs for at least a week because they would melt.
Italian weather experts say Europe's heat wave is one of the five worst in the last 150 years; intense monsoon activity in Africa has been blamed in part for the merciless temperatures. Exacerbating the discomfort: Air conditioning is uncommon in much of northern Europe, and its use is discouraged in the south because of the cost.
However, forecasters predict relief in coming days.
Dominique Escale of Meteo France said temperatures throughout France were expected to drop by midweek — although they would remain well above average. Forecasters were predicting a high of 84.2 for Thursday in the French capital.
The average August temperature in Paris is about 75.
Temperatures were cooler in Britain on Monday, a day after the nation recorded its hottest day ever — 100.58 at Gravesend in southern England. In London, temperatures crept above 100.