ROME, June 27, 2025 (BSS/AFP) - Italy's health ministry warned residents and tourists on Friday of soaring temperatures across the country, issuing a red alert for 21 cities this weekend.

The ministry issued its top red alert for cities including the capital Rome, economic powerhouse Milan and Venice -- where the rich and famous are celebrating the wedding of Amazon tycoon Jeff Bezos.

It said temperatures could rise to 37 degrees Celsius (99 degrees Fahrenheit) in places.

The ministry -- which publishes green, yellow, orange and red heatwave warnings daily for 27 large Italian cities -- advised people not to go outdoors between 11am and 6pm if possible, and seek shelter in airconditioned public places.

In Venice, the temperature was set to hit 32C on Saturday -- when Bezos and Lauren Sanchez are expected to be throwing a dance party starring Lady Gaga -- but feel like around 36C due to humidity.

In Florence, which was already on red alert on Friday, the temperature is forecast to reach 37C on Saturday, while it will go up to 36C on Sunday in the Rome, Milan and Naples.

The warnings follow days of hot weather across the country, including the capital, where holidaymakers have been fined for attempting to cool off in fountains in the historic centre.

The city has put ambulances and medics on standby at busy sites such as the Colosseum, a popular draw for tourists despite the heatwave.

Scientists say extreme heatwaves are a clear sign of global warming and are expected to become more frequent, longer and more intense.

Fuelled by human-caused climate change, 2024 was the warmest year on record globally and 2025 is projected to rank among the top three.