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.

A fourth person died as wildfires blaze on in Spain and parts of Europe worsened by sweltering heat fueled by effects of climate change. Spain's weather agency, Aemet, warned the public on Monday to be "cautious" of the "very high or extreme fire danger" in most of Spain as it reported high 108 degree Fahrenheit temperates on Sunday in Cadiz in the southern tip of Spain only miles to the Strait of Gibraltar.

Raging wildfires in Spain have now encroached upon the southern slopes of the Picos de Europa mountain range, prompting authorities to close a section of the revered Camino de Santiago pilgrimage route.