Greece weather institute warned of temperatures soaring above 40C (104F), as southern Europe is swept by blistering heatwave.

Experts have pointed the finger at climate change driven by the burning of fossil fuels, saying global warming is playing a key role in extreme weather.

“Greece may be more of a focus than Italy for breaking records. Athens, for example, could go up to 42C [108F] on Sunday, which is within shouting distance of the sitting record,” said Rob McElwee, senior weather presenter for Al Jazeera.

Already 11 days into its heatwave, Greece’s national weather institute on Saturday warned reprieve was still days away, setting this up to be the longest hot spell the country has ever seen.

“According to the data, we will probably go through 16-17 days of a heatwave, which has never happened before in our country,” Kostas Lagouvardos, director of research at the National Observatory, told ERT television Saturday.

The previous heatwave record in Greece was set in 1987 when scorching temperatures of over 39C [102F] lasted 11 days.

Greece, which is battling dozens of forest fires, warned people not to venture out unnecessarily due to the baking heat.

The exceptional temperatures also mean key tourist sites such as the Acropolis will be closed during the hottest part of the day.

“This weekend risks being the hottest registered in July in the past 50 years,” said Panagiotis Giannopoulos, a meteorologist with state broadcaster ERT.

Sea temperatures are two to three degrees above normal, the state weather service reported also on Saturday.

The temperatures are taking a toll on people’s health.

Emergency health officials told the state broadcaster at least 38 heatstroke patients were received in the last three days, while hospitals were also seeing cases of fainting and other heat-related conditions.

Authorities meanwhile reported firefighters were still battling 79 forest fires across the country, with their spokesperson Vassilios Vathrakoyannis saying Greece would be on a state of alert through the weekend.

Meanwhile, a large blaze burning on the Greek island of Rhodes for the fifth day has forced authorities to order an evacuation.

According to the Greek coastguard, people were being picked up from Kiotari and Lardos beaches on the east of the Mediterranean island popular with tourists. The coastguard said over 1,500 people have already been evacuated to a safe beach.

Millions of people in southern Europe have similarly been suffering through intense heat this summer as the world appears headed for its hottest July on record.

Soaring temperatures across Italy are taking a heavy toll on residents as they struggle to stay cool during the heatwave.

Alessandro Miani, president of the Italian Society of Environmental Doctors, warned that the ageing populations in Italy and other countries are a concern because heat-related deaths most commonly happen in people older than 80.

“The excessive heat together with humidity can make it difficult for sweat to evaporate, interfering with the body’s ability to regulate its own temperature,” Miani said.

Other southern European countries like Spain have also been grappling with extreme heat this month.

In the Balkans this week, a second storm has left at least three people dead in Serbia, according to local reports.

Meteorologists said the storms were of such powerful magnitude because they followed a string of extremely hot days.