Forecasters predict a record-breaking run across Europe this week, including France, Belgium, Germany and the Netherlands. A World Meteorological Organization spokeswoman said the heat waves bore "the hallmark of climate change".
It comes after sweltering temperatures worldwide made last month the hottest June ever recorded. Much of Europe was engulfed in a sweltering heat wave from the end of June into early July, with temperatures climbing to 44.3 degrees Celsius in France's southern Vaucluse region.
New June highs were set in the Czech Republic, Slovakia, Austria, Andorra, Luxembourg, Poland and Germany.
On Tuesday, meteorological service Meteo France registered 41.2 degrees Celsius in the French city of Bordeaux, breaking a 2003 record of 40.7 degrees Celsius.
Much of France has been issued an orange alert the second highest level of warning, the BBC reported.
Meteo France predicted that temperatures in Paris could exceed 41 degrees Celsius on Thursday, with "absolute heat records" under threat in several cities across the country.
The French capital has never seen the mercury climb above 41 degrees Celsius. The current record of 40.4 degrees Celsius was recorded in 1947.
Comparisons have been drawn to a heat wave France experienced in August 2003, during which heat contributed to almost 15,000 deaths.
The mercury is also expected to climb to 40 degrees Celsius in a string of countries. In an unprecedented move, Belgium has issued a code red weather warning for the entire country. Spain declared a red alert in its Zaragoza region, which was hit by devastating wildfires in June.
The European Commission's Copernicus Climate Change Service says the risk of wildfires is high in Spain and Portugal.
In the Netherlands, the government activated its "national heat plan". In the UK, temperatures are predicted to exceed 35C, and could be the highest ever recorded.
( With inputs from IANS )