Major heat waves across southern Europe have pushed temperatures above 104 degrees Fahrenheit (40 degrees Celsius) 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 107 Fahrenheit (42 Celsius) 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.