In Pictures: Record heatwaves sweep across Europe and US

People cool off at Mondello beach, during a heatwave across Italy.

Students try to shield themselves from the sunlight at the Griffith Observatory gardens in Los Angeles. Over a third of Americans are under extreme heat advisories, watches, and warnings as a blistering heatwave continues across the Southwest and California.

A Jet takes flight from Sky Harbor International Airport as the sun sets over downtown Phoenix. Millions of people around the Southwest are living through a historic heat wave.

Volunteers with the Wells Fargo Technology Services organize water bottles in preparation to pass them out to homeless residents in Phoenix, Arizona. Record-breaking temperatures continue soaring as prolonged heatwaves sweep across the Southwest.

A boy cools himself in a fountain of the central Syntagma square in front of the Greek parliament during a hot day in Athens. Temperatures were starting to creep up in Greece, where a heatwave was forecast to reach up to 44 degrees Celsius in some parts of the country.

A pregnant visitor shields herself from the sunlight during a tour of the Griffith Observatory in Los Angeles. Forecasters say some California residents should prepare for the hottest weather of the year.

Visitors leave the Acropolis archeological site in Athens. The ministry of culture has decided to close the archeological site during the hottest hours of the day, from noon to 5pm, as Greece is hit by a heatwave.

A member of the public holds a cold water bottle on her skin in Rome as Italy is hit by a heatwave.

Spanish authorities say that they have preemptively evacuated some 500 people to avoid a wildfire that has broken out on the Canary island of La Palma. The fire coincides with a heatwave that is hitting southern Europe..

Children cool off at an urban beach of Madrid Rio park in Madrid, Spain. More than 10 of Spain's regions are on red alert for the second day of the latest heat wave, with temperatures topping 40 degrees Celsius.