A freezing airmass causes disruption and deaths across the continent - with the UK days away from its own temperature drop.
Ten people have died in Poland as temperatures as low as -30C (-22F) grip Europe, with snow falling from northern Germany to the beaches of Greece.
The 10 deaths from hypothermia on Sunday happened outdoors or in unheated cottages or abandoned houses, said a government spokeswoman.
It means the cold weather has claimed at least 33 lives in Europe since the weekend.
In Italy, eight people died from the polar blast.
One of those was a man in the basement of an unused building in Milan, while another was found on the street in Florence.
Lumps of ice have also formed in the Adriatic Sea, trapping fishing boats in harbours in Croatia, while there was an Arctic-looking scene in Budapest as large chunks flowed down the Danube.
Beaches in Greece were also covered by snow, including two meters on the island of Evia and heavy falls on Chios and Lesbos - home to thousands of refugees, some of whom are living in tents.
The Met Office said the Shetland Islands were warmer than Crete - despite being thousands of miles further north.
There were also deaths in eastern France on Sunday when a bus skidded on ice, killing four Portuguese people.
In Bulgaria, police said two men from Iraq and Somalia had frozen to death in the mountains as they tried to make their way further into Europe.
Several hundred migrants, mostly from Pakistan and Afghanistan, also endured the cold in an abandoned warehouse in Serbian capital Belgrade, where night temperatures are around -14C.
Aid organisations gave out heaters, blankets and food.
Sky News Europe Correspondent Mark Stone said the situation was serious.
"MSF (Medecins Sans Frontieres) are trying to heat this warehouse but even when they try the temperatures are still below zero."
The conditions in Lesbos in Greece, where many migrants are still being processed, are also "miserable".
Many villages in northern Bulgaria have been left without water or power, as popular Black Sea resorts such as Sunny Beach shivered in -8C (17.6F) temperatures.
Hundreds of planes were also grounded in Turkey's largest city, Istanbul, as 65cm (25.6 inches) of snow blanketed the city.
With many rough sleepers and migrants in danger, the Pope in his Sunday Mass asked for God to "warm our hearts so we'll help".
The Vatican's shelters are open 24 hours a day and it has been giving out thermal sleeping bags and gloves.
Some of its vehicles have also been left unlocked so homeless people can take turns getting warm.
Despite snow in many cities and towns, some Alpine ski resorts are struggling with patchy coverage on the slopes and lower visitor numbers.
France's Haute-Savoie region is worried that water used to produce artificial snow is running out.
While the UK has not been affected by the cold snap so far, there is a warning that most of Britain could see snow by the end of the week, as the Arctic air moves south.