Extreme cold has hit large parts of Europe, with freezing temperatures cracking railroad tracks in Poland, snow blanketing the Turkish metropolis of Istanbul and smog spiking as more coal was being burned to generate heat.

In Switzerland, a skier who had been buried by an avalanche over the weekend died in a hospital of his injuries, authorities said Monday.

The country had issued avalanche warnings several days earlier after heavy snowfall. Officials said the skier and his two companions were buried by an avalanche while skiing off marked trails in the Gstaad area on Sunday. One man freed himself from the snow and then extricated one of the others, but the third man could only be found by rescue crews, who arrived later.

Temperatures dropped to minus 28 degrees Celsius (minus 18 Fahrenheit) in some Polish areas overnight, the coldest night in 11 years. Many trains were delayed on Monday after tracks at two Warsaw railway stations cracked.

Hand-in-hand with the cold came a spike in smog in Warsaw and other parts of Poland, as the cold prompted an increase in burning coal for heat. Air pollution levels were so high in Warsaw that city officials urged people to remain indoors.

Just across Poland’s southwestern border, the Czech Republic experienced the coldest night this year with temperatures dropping below minus 20 degrees Celsius (minus 4 Fahrenheit) in many places.

The lowest temperature — minus 27 degrees Celsius (minus 16 Fahrenheit) — was recorded Monday in Orlicke Zahori, a mountainous village 160 kilometers (100 miles) east of Prague near the Polish border, according to the Czech Hydrometeorological Institute.

The freezing weather was expected to be replaced by heavy snowfall in the northeastern Czech Republic, the institute said.

Wintry weather and freezing temperatures were reported throughout the Balkans, which has created problems with power supplies in Serbia and brought some snow even to Croatia’s Adriatic Sea islands.

In eastern Albania, temperatures dipped as low as minus 13 degrees Celsius (9 Fahrenheit) in Peshkopi, 110 kilometers (70 miles) east of the capital, Tirana. The deep freeze caused water pipes to freeze and created dangerous driving conditions. Icy roads in the city of Pogradec prevented firefighters from arriving in time to a home fire in which a man died early Monday.

In Istanbul, traffic was brought to a halt by the layer of snow covering the city, with cars stalled or skidding on the roads.

In Germany, fresh snow, slippery roads and fallen trees led to several car accidents on Sunday and overnight, the dpa news agency reported. A driver died in southwestern Germany after his car shot over a mound of snow.

The Nordic region also saw snow and subfreezing temperatures, with the coldest temperatures predictably recorded in the Arctic. Norway’s meteorological institute tweeted a tongue-in-cheek message on Monday, saying: “We encourage all knitting lovers to send woolen clothes to their friends in the north.”

In Denmark, police found 17 people ice bathing on Sunday in a lake near Roskilde, 40 kilometers (25 miles) west of Copenhagen. Everyone in the group, aged between 26 and 51, was preliminarily charged with violating pandemic restrictions limiting gatherings to five people. Police said they will all receive a fine, which is 2,500 kroner ($405) for first-time offenders.

(AP)