Italian health officials have intensified heat warnings as southern Europe began a brutally hot week, with temperatures expected to top 40C (104F) on the continent.

The health ministry issued 10 recommendations to protect elderly people and the sick as well as pets, urging people to stay indoors during the hottest hours, drink at least 1.5 litres of water a day and refrain from strenuous exercise at peak daylight times.

The culprit was a high-pressure anticyclone dubbed Cerberus, after the multi-headed dog that guards gates to the underworld in Greek mythology.

Local celebrities went on state-run RAI television to read the recommendations aloud, in the hopes of spreading the message.

The third heatwave in a month is expected to affect much of the Mediterranean and will last until Wednesday.

The mercury in Rome hit 39C (102F) on Monday afternoon.

The Italian capital is expected to be even hotter on Tuesday, as were several other cities, particularly in Sardinia and Sicily.

Power outages were hitting parts of Rome as electric grids suffered under heavier demand from air conditioners as people sought relief.

Italian farm lobbying group Coldiretti, meanwhile, issued an alarm about the plight of domestic and farm animals, noting that cows are producing around 10% less milk as a result of the heat.

In Spain, a wildfire that started on Saturday on the Canary island of La Palma continued to burn out of control on Monday, although authorities says weaker winds and cooler temperatures in the area are helping firefighters combat it.

The blaze has burned some 4,600 hectares (11,300 acres) of mostly woody hill land and some 20 houses and buildings.

More than 4,000 residents were evacuated from their homes on Saturday, but were allowed to return as of late Sunday.

Spain’s Aemet weather agency said the heat wave this week “will affect a large part of the countries bordering the Mediterranean” with temperatures in some southern areas of Spain exceeding 42C (107F).

The agency said it expects temperatures to drop some time on Wednesday.

Spokesman Ruben del Campo said an anticyclone is pushing a hot mass of air from Africa towards Spain and other Mediterranean countries.

The agency predicts that with the heat and very dry air, the risk of wildfires will skyrocket.

Greece got a brief respite from the heat on Monday, with opening hours returning to normal at the ancient Acropolis and other sites.

But two wildfires threatened homes in areas outside Athens, where winds of up to 45mph made the flames difficult to contain.

Most of southern Greece, including greater Athens, was at an elevated level of alert for fire risk, while more extreme temperatures are expected starting on Thursday.

The southern Mediterranean was not alone in suffering.

Authorities in North Macedonia extended a heat alert for the next 10 days with predicted temperatures topping 43C (109F), while Kosovo authorities also issued heat warnings.

“Never in my life have I experienced heat like this before in Pristina,” said Artan Kelani, a 22-year-old student.