ROME (AP) — Major heat waves across Southern Europe have pushed temperatures above 40 C (104 F) in countries including Italy, Spain and Greece, as local authorities issued fresh warnings against the risk of wildfires.

Experts link the rising frequency and intensity of these heatwaves to climate change, warning that such extreme weather events are becoming increasingly common across Europe's southern region.

Severe heat waves were recorded in Italy, Greece, Spain and Portugal before the weekend, with locals and tourists alike taking shelter from the sweltering conditions.

Two-thirds of Portugal were on high alert on Sunday for extreme heat and wildfires, with temperatures expected to top 42 C (107 F) in Lisbon.

In Italy, a few regions — Lazio, Tuscany, Calabria, Puglia and Umbria — were planning to ban some outdoor work activities during the hottest hours of the day in response to the record-high temperatures. Italian trade unions pushed the government to expand such measures at a national level.

On Sunday, the Italian Health Ministry placed 21 out of 27 monitored cities under its highest heat alert, including top holiday destinations like Rome, Milan and Naples.

In Rome, tourists tried to seek shade near popular spots like the Colosseum and the Trevi Fountain, using umbrellas and drinking from public water fountains to stay cool.

Similar scenes were reported in Milan and Naples, where street vendors sold lemonade to tourists and residents to offer some refreshment from the heat.

Greece was again on high wildfire alert because of extreme weather, with the first summer heat wave expected to continue throughout the weekend.

A large wildfire broke out south of Athens on Thursday, forcing evacuations and road closures near the ancient Temple of Poseidon. Strong winds spread the flames, damaging homes and sending smoke across the sky.

Greek authorities deployed 130 firefighters, 12 planes and 12 helicopters to battle the blaze, while police evacuated 40 people, with five areas under evacuation orders.

In Spain, locals and tourists were desperately trying to keep cool this weekend, as the country sizzled in temperatures as high as 42 C (107 F) in the southern city of Seville along with other locations in southern and central parts of the country.

Southern regions of Spain recorded temperatures above seasonal averages, prompting health alerts and safety recommendations from authorities. The country’s national meteorological service Aemet has said that June is set to break yet another record, becoming the hottest such month since records started.

Experts warned that intense heat can affect daily life, especially for vulnerable populations such as the elderly and children.

Local authorities advised against physical activity during the hottest hours of the day, and recommended drinking plenty of fluids.

A Lancet Public Health study published last year highlighted the increasing risk of heat-related deaths because of climate change. The study predicted that heat-related deaths could more than quadruple by mid-century under current climate policies.

While more people currently die from cold than heat, the study stressed that rising temperatures will offset the benefits of milder winters, leading to a significant net increase in heat-related mortality.