A powerful heatwave has struck Southern Europe, with temperatures in Spain soaring to 46 degrees Celsius, while nearly all of continental France has been placed on alert.

Extreme heat, worsened by fossil fuel pollution, has scorched Portugal, Spain, France, Italy, and Greece for several days, as Southern Europe experiences its first major heatwave of the summer.

High temperatures have prompted authorities in several countries to issue new health warnings and mobilize firefighters to prevent wildfires. More than 50,000 people in Turkey have been evacuated from their homes due to wildfires, according to the Disaster and Emergency Management Authority of the Ministry of Interior.

At a development conference in Seville, UN Secretary-General António Guterres stated yesterday that extreme heatwaves are no longer rare events—they have become the new normal.

In his home country Portugal, Mora, about 60 miles east of Lisbon, recorded a temperature of 46.6 degrees Celsius. Meteorologists are working to confirm whether this is a new June record.

Southern Spanish cities are expected to endure temperatures above 40°C for the next three days, with nighttime temperatures not dropping below 25°C until Thursday morning. Doctors have expressed concern over the combination of hot days and uncomfortably warm nights, which can cause fatal stress to the human body.

In Italy, where 21 out of 27 cities were placed under the highest heat alert level on Sunday, hospital admissions in some of the hottest regions like Tuscany have risen by 20 percent. People have been advised to avoid going outdoors between 11 a.m. and 6 p.m.

In France, heat warnings have for the first time in history covered almost the entire mainland. Meteo-France placed 88 percent of administrative regions under the second highest heat alert level.

“This is unprecedented,” said Ecology Minister Agnès Pannier-Runacher.

The French government has asked businesses to adjust working hours to protect workers from the heat, and 200 public schools will be partially or fully closed on Monday and Tuesday. The first wildfire of the summer broke out in southwestern France over the weekend, burning 400 hectares and forcing the preventive evacuation of over 100 people from their homes.

Spain, which has faced the worst weather conditions, recorded a June temperature record of 46 degrees Celsius on Saturday afternoon in El Granado, in the Andalusian province of Huelva. The previous highest June temperature was 45.2 degrees Celsius, recorded in Seville in 1965.

Sunday was the hottest June 29 ever recorded in Spain, according to data from the Spanish Meteorological Agency Aemet, dating back to 1950. The heatwave is expected to last until Thursday.

In Portugal, where seven out of 18 regions are under red warnings for “extreme risk,” meteorologists expect cooling on Wednesday evening.

Northern countries are also at risk. Germany’s meteorological service warned that hot and dry weather increases the risk of wildfires, and some cities are limiting water use as temperatures in parts of the country approached 40 degrees Celsius by Wednesday.

In Brandenburg, the federal state surrounding Berlin, the government urged employers to consider heat risks for their workers.

“Companies are required to comply with workplace heat protection regulations,” said regional Health Minister Britta Ernst, including maintaining acceptable indoor temperatures and protecting employees from excessive sun exposure.

In the UK, temperatures are forecast to reach 34°C in London and southeastern England, with the Meteorological Office warning that high heat and humid conditions will be “quite uncomfortable” for outdoor workers and for people attending the start of Wimbledon after leaving Glastonbury.