Tourists stand in front of a cooler installed around the Colosseum amid a heatwave in Rome, Italy, on Friday. Reuters

Temperatures were forecast to hit 40˚C in parts of the country, according to the official air force weather service, while the health ministry issued red alerts for Rome and Palermo among other cities.

Weather website Il Meteo blamed an African anticyclone it dubbed "Minos," who in Greek mythology was the son of Zeus. After his death, Minos became a judge of the underworld.

In Rome, where the air force recorded a peak of 39˚C on Thursday afternoon, the city hall has installed potted palm trees at bus stops to provide some shade.

While the capital has many parks and is dotted with drinking water fountains in addition to the decorative ones, there are also many streets and piazzas with little to no cover from the sun.

The occasional palm was not enough to offset the sauna-like heat and during lunchtimes this week, many have spurned outside tables for the cool of air-conditioned restaurants.

"We'll go back to the hotel for a while to avoid the hottest hours," Anna Verna, an Italian tourist to Rome, told AFP on Friday while visiting an area near the famous Spanish Steps.

"Then we'll go out again... Rome is beautiful, so we want to enjoy it even in the heat."

Environmental campaign group Greenpeace took a thermal camera onto the streets of Rome and found temperatures above 50˚C at certain spots, including the Colosseum.

Last year, Rome recorded a record peak temperature of 42.9˚C on July 18, according to city hall. "A record, unfortunately, that we risk breaking this summer," said Sabrina Alfonsi, lead councillor for the environment.

"Summer has already exploded, even though it is still June." Human-caused climate change is heating up the planet at an alarming rate, sparking repeated intense heatwaves, the global scientific community agrees.

Agence France-Presse