ROME, July 19 (Xinhua) -- Several Italian cities were placed under the highest heat warning on Friday, as a heatwave causing extreme temperatures is expected to peak over the weekend.
The red alert -- the highest in the country's four-tier system -- will be in place for three days in 17 out of the 27 cities included in the national monitoring system operated by the Health Ministry, and another five cities are on the second-highest orange alert.
Turin, Bologna, Verona, and Trieste have been among the cities hardest hit by the heatwave in the north, while Florence, Rome, and Perugia in central Italy, and Bari and Palermo in the south are also experiencing extremely high temperatures.
In several regions, especially in metropolitan areas, temperatures are expected to exceed 40 degrees Celsius during the next 48 hours, to be eased by a wave of cooler air gradually arriving in some of these areas by Sunday afternoon, according to weather forecasts by Italy's Air Force and the online weather service ilMeteo.it.
In the Italian system, a red alert signifies serious health risks for all citizens.
The Health Ministry's warning hit the headlines in the Italian media, since the country is entering the busiest holiday season when millions of people -- including foreign tourists and residents -- are seeking to pursue a multitude of outdoor activities.
Linked to the orange and red alerts, an increased risk of wildfires has also been reported in some areas, including Sicily's regional capital Palermo where the local authorities have issued the highest wildfire risk warning for this weekend. Tuscany also remains on high alert after at least 13 wildfires were reported and extinguished across the region on Thursday, according to local authorities.