Authorities in northern France raced Wednesday to restore power to thousands of homes after widespread outages struck during a punishing heat wave that has gripped much of Western Europe for days.
Officials said health care facilities and other critical infrastructure were being given priority as crews worked to reconnect affected areas. Generators were also deployed to retirement homes following Tuesday's blackout, which authorities linked to a transformer failure.
"The incident was accidental and linked to the ongoing heat wave," officials said in a statement. "No one was injured."
Record-breaking temperatures across Europe, reaching as much as 18 degrees Celsius (32 degrees Fahrenheit) above normal, according to the Reuters Climate Monitor, have disrupted transport networks and forced schools and tourist sites to close.
Weather agency Meteo-France said the conditions are comparable to a heat wave in August 2003 that lasted 16 days and caused an estimated 80,000 excess deaths across Europe.
It was unclear how long the current heat wave, driven by a weather pattern known as an Omega block that allows temperatures to build day after day, would last.
Europe is warming at more than twice the global average, the World Meteorological Organization has said, making prolonged heat waves increasingly likely.
The heat wave has forced builders to alter working hours so employees can avoid the worst conditions, while retailers struggle to meet demand for fans and portable air conditioners and farmers harvest grain at night after afternoon work was banned because of fire risks.
Dozens have drowned while trying to escape the heat by jumping into bodies of water.
In Britain, the grid operator asked generators to make more power available amid soaring temperatures expected to break records later Wednesday.
With temperatures in the upper 30s Celsius, British health authorities issued a red heat health alert for only the second time, warning of a risk to life for healthy people as well as the ill and elderly.
Britain's train operators advised travelers to make only essential journeys on Wednesday and Thursday, the hottest days of the week, as the heat prompted speed restrictions.
In southeastern France, two children, ages 2 and 4, who died in a hot car outside their family home were found in autopsies to have succumbed to excessive heat.
Their mother said the children were in the car without her knowledge, the regional prosecutor said.
Italy's Health Ministry issued its highest heat alert for 16 cities, including Florence, Milan, Rome, Turin and Verona.
Conditions were expected to worsen further, especially across central and northern regions, with the heat wave likely to peak between Sunday and Monday, meteorologists said.
Temperatures could reach 41 degrees Celsius (106 degrees Fahrenheit) between Tuscany and Emilia-Romagna, while in coastal areas such as Liguria, the combination of heat and extreme humidity could push perceived temperatures as high as 45 degrees Celsius (113 degrees Fahrenheit).