A total 20 departments in northern France were placed on the maximum red heatwave alert on Thursday, July 25 - the peak of the current 'canicule', forecasters said.
Another 60 have been placed on the second-highest orange alert in the latest update from national forecaster Météo France.
Paris is expected to reach a record-breaking 42C - smashing the 1947 high of 40.4C - and at 6am the temperature was 26.5C in Paris and 27.1C in Bordeaux. Experts warned that temperatures would range from 37C to 42C across a large part of the country, with peaks at 43C locally.
The national record, 46C recorded at Vérargues, Hérault, during June's heatwave, is not expected to be broken. On Wednesday, new record highs were set in Brive (42.1°C), Bordeaux (41.2°C), Châteauroux (40.8°C) and Rennes (40.1°C).
As well as Paris, record temperatures are set to be broken in Lille, Rouen, Orléans, Reims, Dijon, Nancy and Strasbourg on Thursday, the forecaster warned, saying the mercury across much of the north and northwest could nudge the 40C mark.
In Paris, only vehicles with Crit'Air stickers 1 and 2 are allowed, while Lille, Lyon, Strasbourg and Annecy have restricted traffic to vehicles with stickers numbered 1,2 and 3. In Lille, carpool vehicles are allowed into the city regardless of which sticker they have.
The red alert, the highest of the four-colour alert levels, is activated in the event of a heat wave of "exceptional" intensity - and takes into account the significant expected health impact. These weather alerts are issued as part of a collaboration between the national weather agency and the Ministry of Health.
It means the public needs to take "absolute vigilance" because a "dangerous" weather phenomenon of "exceptional intensity" has been forecast. The public is urged to keep up to date with the news and weather forecasts - and follow public safety advice.
Météo France warned: "everyone is at risk, even healthy people", but added: "The danger is greater for seniors, people with chronic illness or mental health issues, people who take regular medication and people who are isolated."
The advice for people is to stay indoors in a cool place during the hottest part of the day. Drink regularly.
[#Canicule] Soyons attentifs envers les personnes vulnérables qui nous entourent !— Ministère des Solidarités et de la Santé (@MinSoliSante) July 25, 2019
. @ameli_actu vous explique comment identifier et réagir face à une insolation : https://t.co/jlsJ7sJtnL pic.twitter.com/mxFbOpOlWL
- check in with elderly, chronically ill or isolated people you know twice a day. Accompany them to a cool place if possible
- Use a fan and/or air conditioning if available. Otherwise try to go to an air-conditioned location (such as a supermarket or cinema) for two to three hours a day
- Wet your body several times a day with a mist, a washcloth or by taking showers or baths
- Adults and children: drink plenty of water, the elderly: drink 1.5L of water per day and eat normally
- If you have to go out wear a hat and light clothing - and be aware of the symptoms of heatstroke - a fever over 40C, hot, red and dry skin, headaches, nausea, drowsiness, intense thirst, confusion and convulsions
The Ministry of Health has set up a hotline number - 0800 06 66 66 66 - for people suffering from the heat. It is free from a landline and operates from 9am to 7pm.
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