Regional authorities in Sicily recorded temperatures of 48.8 degrees Celsius Wednesday as an anticyclone dubbed "Lucifer" swept the country -- which if confirmed would be a new Italy record.
The blistering temperature was recorded near Syracuse, beating Italy's all-time record of 48.5 degrees in Sicily in 1999, although a spokesman for the national meteorological service told AFP this still had to be validated.
In Malta, the maximum temperature recorded on Wednesday was 40.1°C, a Met Office spokesperson confirmed.
Elsewhere in southern Italy, the anticyclone was forecast to send the mercury rising to 39-42 degrees before sweeping northwards, with weekend temperatures of up to 40 degrees in the central regions of Tuscany and Lazio, which includes Rome.
As the capital warmed up on Wednesday, tourists sought out shade and water.
"I kinda like it, it's the goal of summer to be hot and sweat and just enjoy it!" said Nora Vert, a 20-year-old from France.
The heat has raised fears for the fires that have blighted Sicily and the region of Calabria all summer, many caused by arson but fuelled by warm winds and dry soil and plants.
Firefighters said earlier Wednesday they had recorded 300 interventions in the past 12 hours, while a 77-year-old man died from burns received while trying to shelter his herd in the countryside near Reggio Calabria.
Elsewhere in Calabria, fires threatened the Aspromonte mountain range, designated as a UNESCO area of international geological significance.
The deputy head of environmental NGO WWF Italy, Dante Caserta, called for more resources, such as air support, to quell the flames "or it will be too late, and we will lose forever a priceless heritage".
The Madonie mountain range, near the Sicilian capital Palermo, has also for several days been besieged by flames that have destroyed crops, animals, homes and industrial buildings.
Sicily's governor, Nello Musumeci, called for a state of emergency to be declared for the mountains, while Agriculture Minister Stefano Patuanelli visited Wednesday to meet local mayors around Palermo.
"The fires are an emergency that need immediate responses, first and foremost with the relief that must be given to those who have lost everything," Patuanelli said.
Blazes have also devastated Sardinia, with 13 fires recorded during the day on Tuesday. Over 20,000 hectares (50,000 acres) burned last month in the west of the island during the worst fires seen in decades.
Southern Europe has experienced intense heatwaves and wildfires this summer as experts warn climate change increases the intensity and frequency of such extreme weather events.