Italy is placing all its 27 major cities under its highest heat alert on Thursday, ​as the country’s fourth heatwave of the summer ‌intensifies, the health ministry said.

Twenty-five cities were put on red alert on Tuesday and Wednesday, with the only two ​currently on a lesser amber alert, Messina and ​Reggio Calabria in the far south of the ⁠country, moving up to the maximum level on ​Thursday.

A red alert indicates a potential health emergency with ​prolonged high temperatures posing a serious health risk to the entire population, including young and healthy people.

Local authorities urged residents in affected ​areas to avoid exposure to heat and direct ​sunlight during the hottest hours of the day, between 11:00 a.m. ‌and ⁠6:00 p.m., stay indoors where possible and drink plenty of fluids.

A spokesperson at the health ministry said it was the first time this year that all 27 ​cities had been ​issued with ⁠a red alert, but could not confirm if this had ever happened in previous ​years.

Temperatures have climbed to 40 degrees Celsius (104 ​degrees ⁠Fahrenheit) in some areas of Italy and little relief is expected before the weekend. Forecasters say the heatwave is ⁠being ​fuelled by a North African anticyclone ​that has strengthened over the Mediterranean and stretched across much of ​Europe.