Heat waves are occurring with more frequency, intensity and prolonged duration both regionally and globally. Many countries and regions issued warnings due to extreme heat.

Extreme heat across the globe

Excessive heat warnings remain in place in many areas across the U.S. and are expected to last at least through Monday.

In Arizona's largest metro area, Phoenix and surrounding communities flirted with a high of 46 degrees Celsius on Sunday.

In Nevada, the first excessive heat warning of the summer runs through Monday evening for the Las Vegas metro area. Daytime cooling centers are open across the region.

It was 39 degrees Celsius Friday at Harry Reid International Airport in Las Vegas, ending 294 days of temperatures staying below 38.

Elsewhere, the heat and severe weather remained a concern throughout the U.S. southeast.

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Some European countries are also experiencing extremely hot weather.

According to the European Environmental Agency, Europe is facing its warmest decade on record, with an average temperature increase of 1.11 degrees Celsius to 1.14 degrees Celsius warmer than pre-industrial levels.

Temperatures soared to 44 degrees Celsius in the south of Spain, while the capital Madrid baked at over 40 degrees Celsius. As many as 13 provinces also hit this milestone.

Last week, Italy sweated through its first heat wave of the year, with temperatures climbing to the mid-30s in parts of the country. An "orange alert" for heat was issued on June 22 in its cities.

"Heat wave climatic conditions can pose a risk to the health of the population," the authorities warned.

Ways to beat the heat

Scientists and medical experts predict that deaths caused by extreme heat will rise as heat waves increase without more action to combat climate change, making people especially vulnerable in areas unaccustomed to warm weather.

According to the U.S. Environmental Protection Agency, programs that install cool or green roofs and plant trees and vegetation can help keep buildings and their surroundings cooler. These measures also reduce electricity demand, which helps improve the reliability of the electric system, particularly during heat waves.

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(With input from AP)

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