BELGRADE, Serbia >> No wonder it’s been dubbed “Lucifer.”

A relentless heat wave that gripped parts of Europe this week has sent temperatures soaring to record highs for several days, causing at least two deaths and prompting authorities to issue severe weather warnings.

“It is just too much,” real estate agent Sasa Jovanovic, 52, said during an early morning walk in Serbia’s capital, Belgrade, where the temperature was forecast to hit 39 degrees Celsius (102.2 degrees Fahrenheit) today. “Sometimes it feels as if I cannot breathe.”

The extreme heat stifling Serbia, Romania, Croatia and parts of Spain, France and Italy has fueled wildfires, damaged crops and strained energy and water supplies. Authorities in some areas issued traffic restrictions and banned outdoor work during the hottest part of the day.

Spain’s national weather service today issued an emergency warning for high temperatures in 31 of the country’s 50 provinces as forecasts predicted temperatures of up to 44 C (111.2 F).

Western and northern Europe, in contrast, was experiencing colder and wetter weather.

Although southern Europe is used to scorching summers, meteorologists have warned that hot spells lasting several days aren’t that common.

The public health institute in Belgrade issued heat instructions, telling people to keep wet towels on windows if there is no air conditioning, and avoid physical strain and alcohol.

Thousands of residents sought refuge from the heat at the city’s recreation area, swimming in the local lake and the Danube or the Sava rivers. Some of those who ventured to the city center dipped their feet or wet their hair in the fountains.

The high temperatures came as a shock to Australian Mira Balic, who was visiting Serbia at a time when it’s winter in the Southern Hemisphere. Belgrade was among the hottest cities in Europe today and hotter than Egypt’s capital, Cairo — which is normally far hotter than central Europe.

“I came here from Australia, where the temperature is 4 degrees (Celsius; 39.2F,” Balic gasped. “This heat is killing me!”

Animal rights groups urged citizens to place plastic bowls with water outside their buildings and in parks for the city’s many stray dogs.

In Croatia, health authorities have reported a surge in emergency calls over the past week. They appealed to the thousands of tourists vacationing along the country’s Adriatic coast to be careful on the beaches and while traveling.

In Romania, police banned heavy traffic on major roads in daylight hours during the weekend because of the heat wave, while trains slowed down. A train service in southern Serbia also was delayed earlier this week after tracks buckled in the heat.

Romania reported two heat-related deaths — a 45-year-old man collapsed and died Friday while working in a field in the northeast, while a 60-year-old man died of a heart attack in the street in an eastern port Thursday.

The state railway company in neighboring Hungary said it would distribute water at busy terminals. At the Budapest Zoo, Beliy and Seriy, a pair of 2-year-old polar bear cubs, were given huge chunks of ice and freezing-cold watermelons to help them withstand the weather conditions.

Some 15 wildfires have been reported in Albania, and dozens of others throughout the region. Hot and dry weather has scorched crops amid fears of water shortages in Italy and Serbia as authorities appealed for care in consumption.

In the Alpine nation of Slovenia, authorities reported earlier this week the first-ever “tropical night” at 1,500 meters (4,920 feet) in the mountains, meaning temperatures were higher than 20 C (68 F) during the night.