Five deaths related to the heat were recorded yesterday, following the death on Sunday of a man in Murcia, southern Spain.
In The Netherlands, two people succumbed to the heat during the opening day of an annual four-day walk in the eastern Nijmegen region.
In France's southwest Bordeaux region, sweltering at 38 degrees C, two octogenarians fell victim to hyperthermia.
An 85-year-old man died in hospital and a woman, 81, at her home.
In Spain, a 44-year-old man died of heat exhaustion at Orense, in the northwestern region of Galicia, after he had reportedly been working outside as temperatures hit 41.5 C.
Britain braces for hottest day
Britain, which suffered the hottest day of the year yesterday, was braced for its hottest day on record as forecasters predicted temperatures could reach 39 C in parts of England today.
The London underground system, the oldest in the world, was a furnace yesterday with a record temperature of 47 C.
Bus passengers fared even worse, with temperatures on buses in the City of London, the main financial district, reaching 52 C.
The high temperatures revived the spectre of the 2003 heatwave, which killed 30,000 people in Europe, half of them in France.
Meteorologists in Germany are warning their countrymen that Thursday could be the hottest day in the year at 38 C, and July as a whole could be the hottest month in a century.
Across the Channel, around a quarter of France was affected by the heatwave on Tuesday, predominately in the southwest.
Cyclists competing in the Tour de France sweated through the 187-kilometre stage in the Alps, which includes four notorious climbs.
French authorities, who were accused of reacting too slowly to the tragic 2003 heatwave, were leaving little to chance this year, and hospitals and retirement homes were on high alert.
Italy's main farmers' union said the country was suffering one of the worst droughts in 30 years with the situation in the north and the centre particularly bad.
Belgium's royal meteorological institute announced "tropical temperatures" of between 29 C and 33 C, with highs of 35 C in the north.
The Netherlands, Finland and Sweden all reported unusually hot weather.