The summer's first major heatwave has scorched countries along the northern coast of the Mediterranean and the sea itself hit a record temperature for the month of June, meteorologists said.

France's national weather agency placed Paris and 15 other departments on its highest weather alert for Tuesday, with temperatures of up to 41 degrees Celsius (105.8 Fahrenheit) predicted.

Police ordered all but the least polluting vehicles off the road between 5:30 am (0330 GMT) and midnight in the Ile-de-France region that includes the capital because of harmful ozone pollution.

Speed restrictions were also imposed.

Ambulances stood ready near tourist hotspots as experts warned that such heatwaves, intensified by climate change, would become more frequent.

In Turkey, rescuers evacuated more than 50,000 people threatened by a string of wildfires. Most were from the western province of Izmir, where winds of 120 kilometres (75 miles) per hour fanned the blazes.

Firefighters also battled blazes that broke out Sunday in Italy, fed by the heat and whipped up by strong winds, while about hectares (988 acres) of vegetation were destroyed by fire off a motorway in southern France.

The blaze was blamed on a poorly extinguished barbecue.

Cities were meanwhile offering different ways to stay cool, from free swimming pools in Marseille and parks open until 11:00 pm in Bordeaux, to free guided tours for the elderly in Venice's air-conditioned museums.

- Records -

Temperatures in southern Spain soared to 46C on Saturday -- a new record for June -- the national weather agency said.

The Mediterranean Sea itself was warmer than usual, recording a new June high of 26.01C on Sunday, according to French weather service scientist Thibault Guinaldo, citing data from EU monitor Copernicus.

Agathe Lacombe, a tourist from Strasbourg visiting Madrid with her family, called the heatwave "a bit difficult".

"You have to adapt your whole day's planning, do everything in the morning and come home at the hottest times to find a bit of cool," she told AFP.

Portugal's national meteorological agency said Monday the temperature had reached 46.6C in Mora on Sunday, which experts cited by local media said was a new June record.

Seven regions in central and southern Portugal, including the capital Lisbon, were placed on red alert for the second day running Monday, with fire warnings in many forested areas.

In Italy, images posted by local media showed people running into the sea at a beach resort in Baia Domizia near Naples as flames tore through pinewoods behind them.

"I have never experienced anything like this, we were surrounded by flames at least thirty meters high, smoke everywhere," the mayor of nearby Cellole, Guido di Leone, wrote on Facebook.

- Peak -

In France, where the night from Sunday to Monday was the highest ever recorded for June, the heatwave is due to peak on Tuesday and Wednesday.

The government said it expected nearly 1,350 schools to be partially or completely shut on Tuesday -- nearly double the number on Monday.

The sizzling temperatures will stretch to the end of the week and beyond in Italy, according to Antonio Spano, founder of the ilmeteo.it meteorological website.

Authorities have issued red alerts for 18 cities over the next few days, including Rome, Milan, Verona, Perugia and Palermo.

Italy's opposition parties urged the government Monday to improve conditions in the country's stifling prisons, which are notoriously overcrowded.

The same problem also affects French prisons and the prison governors' union called the situation "unbearable".

Heat "exacerbates existing frustrations and tensions", added Wilfried Fonck, national secretary of the Ufap Unsa Justice prison union.

"The situation needs to be defused to stop things from escalating more than usual," he told AFP.

Scientists say climate change is stoking hotter and more intense heatwaves, particularly in cities where the so-called "urban heat island" effect amplifies temperatures among tightly packed buildings.

- 'Not normal' -

In Croatia, the vast majority of the coastline was on red alert, while an extreme temperature alert was issued for Montenegro.

With little relief in sight, the meteorological service in Serbia warned that "severe and extreme drought conditions prevail" in much of the country.

In Madrid, where temperatures approached 40C, 32-year-old photographer Diego Radames told AFPTV he found the June heat "not normal".

"As the years go by, I have the feeling that Madrid is getting hotter and hotter, especially in the city centre," he added.

Further north, Britain's Met Office weather service upped the number of amber heat alerts on Monday to seven regions, as temperatures hit 34C in London and southeast England.

The BBC said temperatures at Wimbledon, where the annual tennis championships got under way, hit 31.4C by 1500 GMT, making it the hottest opening day on record.

"Wimbledon when it's really hot is quite sweaty. Last time we were very hot so this time we've got rose (wine) in a cooler so we can do a better job," said spectator Sean Tipper, 31.

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