A further fire was reported in Florence.
For weeks now firefighters have been battling forest and bush fires throughout the country. Many have been caused by human negligence or arson, and then exacerbated by dry conditions and wind.
Firefighters were also battling a forest fire near the Italian-Slovenian border in the municipality of Doberdò, south of Gorizia, officials said. Images showed thick clouds of smoke billowing out of the woods. A section of motorway near Monfalcone, between Triest and Venice, had to be closed.
Parts of the islands of Sicily and Sardinia have been placed on the highest wildfire alert level.
In France, two major wildfires were spreading in the southern part of the Atlantic coast, despite the efforts of firefighters who have been battling the flames for the past week.
The fires spread to burn a further 300 hectares late on Tuesday, Gironde officials said.
A total of 20,600 hectares of land has burned near Landiras and Teste-de-Buch, south of Bordeaux.
Strong winds and droughts in some areas are fanning other fires in France, including in Brittany, where a wildfire tore through more than 1,700 hectares of forest near Brasparts. Hundreds of people had to be brought to safety.
The heatwave is also affecting Britain. Dozens of trains were cancelled or delayed across England on Wednesday because of problems caused by the extreme heat that came a day after record temperatures were registered throughout the country.
Meanwhile Britain is bracing for more extreme weather, with a yellow warning in place for heavy showers and thunderstorms in parts of England that could bring disruption later on Wednesday.
