The fires have spread over the regions of Extremadura, Galicia, and Castile and Leon, forcing authorities to suspend rail services and cut access to roads in the area, as well as blocking a 50-kilometre stretch of the popular Camino de Santiago pilgrimage trail.

Spain's worst wave of wildfires on record spread to the southern slopes of the Picos de Europa mountains on Monday and prompted authorities to close part of the popular Camino de Santiago pilgrimage route.

This year is turning into one of the worst fire seasons in recent memory in Europe. Firefighters are struggling to contain out-of-control wildfires in western Spain and Portugal.

Spain's weather agency warned the public on Monday to be "cautious" of the "very high or extreme fire danger."

Firefighters have spent days battling blazes in Greece, Portugal, Spain and elsewhere. Forecasters said temperatures could pass 111 degrees in some places on Thursday.

In Spain, as temperatures soared above 100 degrees Fahrenheit and wind gusts reached 45 miles per hour, officials ordered the evacuation of 3,700 people across 16 municipalities, the Guardian reported. One man died from burns suffered while trying to free horses from a stable amid the blaze.

A 85-year-old man has died in Spain after the country saw the start of the second official heat wave of the year, authorities said on Monday, as temperatures continue to soar. The man died in Badajoz,

France sent two teams of 100 firefighters, who were “currently arriving,” Virginia Barcones Sanz, the director general of civil protection and emergencies in Spain, told reporters on Monday. Germany is deploying a team of 66 firefighters with 21 vehicles, while Finland is sending 30 firefighters, she said.

Europe’s next heat wave is already building over the Iberian peninsula, potentially testing more temperature records after an unseasonably cool start to August.

Defence minister attributes fires to climate change, heat wave. The Interior ministry said 27 people have been arrested and 92 were under investigation for suspected arson since June.