Around 68,000 households in France are without power and sales of air conditioners are skyrocketing. France's national temperature indicator - an average of day and night temperatures at more than 30 stations - hit 30 degrees Celsius on Wednesday, the highest since records began in 1947. That was slightly higher than Tuesday's record of 29.8 degrees Celsius.
The Spanish weather agency Aemet has measured the highest June temperature on the Spanish mainland since at least 1950, AFP reports.
On Monday, the Spanish heat reached almost 28.1 degrees Celsius on average during the day, a new record, and on Tuesday it was even warmer, just under 28.2 degrees Celsius.
Red warnings
A temperature of 35.7 degrees Celsius in Surrey in southern Britain on Wednesday marks the hottest June day so far in the country, Sky News reports.
A red heat warning is in effect in 58 French departments on Wednesday. In 31 departments, the lower orange warning applies, the weather agency Météo France announced.
In 35 departments, the risk of forest fires is assessed as high.
"A scorching sun is shining across the country, and the atmosphere is warming up rapidly. These sunny and oppressive conditions will persist in most regions throughout the afternoon, except in the southeast and northwest," writes Météo France.
1,800 French schools are closed due to the heat.
The International Federation of Red Cross and Red Crescent Societies (IFRC) has warned that the heat could quickly become a matter of life and death for the most vulnerable, AFP reports.
More countries warn
"Extreme heat kills," warns the World Health Organization (WHO) on X.
The UN agency urges the public to learn to recognize the signs of heatstroke: confusion, collapse and convulsions. WHO recommends using electric fans only when the temperature is below 40 degrees Celsius. If the air is warmer, the fan will instead warm the body.
Heat warnings have also been issued in large parts of Spain and Italy.
The heat wave is also pushing up temperatures in northeastern Europe. Poland, Croatia and Hungary, among others, have issued warnings for the next few days. In several countries, temperatures are expected to reach around 40 degrees Celsius.
