Sánchez cited figures released Monday from the Carlos III Health Institute which estimates the number of heat-related deaths based on the number of excess deaths when compared to the average in previous years.

The institute has stressed that these figures are a statistical estimate and not a record of official deaths.

“During this heatwave, more than 500 people died because of such high temperatures, according to the statistics,” Sánchez said.

READ MORE: Why have so many died during this heatwave in Spain?

“I ask citizens to exercise extreme caution,” he said, noting that the “climate emergency is a reality”.

Spain was gripped by a heatwave affecting much of Western Europe which pushed temperatures as high as 45 degrees Celsius (113 degrees Fahrenheit) in some regions last week, sparking dozens of wildfires.

MAP: Where are Spain’s wildfires raging?

The blazes forced the evacuation of thousands of people and claimed at least two lives — that of a firefighter and a shepherd who got caught up in the flames in northwest Spain.

The July 9th-18th heatwave was one of the most intense ever recorded in Spain, meteorological agency AEMET said Wednesday.

“At a minimum, it is the third most intense heatwave in terms of its geographic extension and duration” since modern records began in 1975, AEMET spokeswoman Beatriz Hervella said.

Only two other heatwaves lasted longer – one in July 2015 that lasted 26 days and another in August 2003 that went on for 16 days, she added.