A punishing heatwave broke a string of records in France and Britain on Friday as Spain battled to contain forest fires that forced hundreds from their homes.
The hot weather is in line with warnings from scientists that heatwaves will be more intense and hit earlier than usual thanks to climate change.
In Spain, forest fires burned up to 7,000 hectares of land in the northwest Sierra de la Culebra region, forcing some 200 people from their homes.
Firefighters were battling fires in several other regions, including woodlands in Catalonia where weather conditions complicated the fight.
Prime Minister Pedro Sanchez praised firefighters "who risk their lives on the frontline of fires" on Friday, which is also World Day to Combat Desertification and Drought.
Temperatures were above 35C Friday in most parts of the country and will top 40C in some areas.
In France, temperatures also climbed Friday with one-third of French departments at the highest or second-highest heat alert level.
Much of the country's southwest will see thermometers top 40C, prompting warnings for the vulnerable.
"Hospitals are at capacity but are keeping up with demand," Health Minister Brigitte Bourguignon told reporters in Vienne, near Lyon in the southeast.
Schoolchildren have been told to stay at home in the 12 departments at alert level "red" and the health ministry activated a special heatwave hotline.
"This is the earliest heatwave ever recorded in France" since 1947, said Matthieu Sorel, a climatologist at weather authority Meteo France.
With "many monthly or even all-time temperature records likely to be beaten in several regions," he called the unseasonable weather a "marker of climate change".
The heatwave has spread up from north Africa through Spain, also affecting Italy and the United Kingdom.
Several towns in northern Italy have announced water rationing and the Lombardy region may declare a state of emergency as a record drought threatens harvests.
The UK recorded its hottest day of the year on Friday with temperatures reaching over 30C in the early afternoon, meteorologists said.
It was the third day in a row that temperature records had been broken in the UK, where it was over 28C on Wednesday and 29.5C on Thursday.
Experts warned that the high temperatures were caused by worrying climate change trends.
"As a result of climate change, heatwaves are starting earlier," said Clare Nullis, a spokeswoman for the World Meteorological Organization in Geneva.
"What we're witnessing today is, unfortunately, a foretaste of the future" if concentrations of greenhouse gases in the atmosphere continue to rise and push global warming towards 2C from pre-industrial levels, she added.
In France, special measures have been taken in care homes for elderly people, still marked by the memory of a deadly 2003 heatwave.
Buildings are being sprayed down with water to cool them and residents are being rotated through air-conditioned rooms.
"We're taking even more care than usual with the old folks. It's tough for them. They're often alone, worn down physically and unable to act independently," said Sarah Jalabert, a nurse making home visits in the Tarn department.
In the Gironde department, which includes Bordeaux, authorities said all public events outdoors or in non-air-conditioned venues would be banned from 2:00 pm (1200 GMT) on Friday, a measure set to be broadened across the region.
And speed limits in several regions, including around Paris, have been reduced to limit the concentration of harmful smog or ozone in the heat.
Electric grid operator RTE said increased use of fans and air-conditioners was also driving up power consumption.