This part of Europe is not unused to cold, but the current freeze, which spread to most of the region last week, came after a period of relatively mild weather. Many were shocked when temperatures in some parts plunged Monday to minus 20 Celsius (minus 4 Fahrenheit).
"Just as we thought we could get away with a spring-like winter ..." lamented Jelena Savic, 43, from the Serbian capital of Belgrade, her head wrapped in a shawl with only eyes uncovered. "I'm freezing. It's hard to get used to it so suddenly."
Officials have appealed to people to stay indoors and be careful. Police searched for the homeless to make sure they didn't freeze to death. In some places, heaters will be set up at bus stations.
Still, 18 people, most of them homeless, died in Ukraine from hypothermia and nearly 500 people sought medical help for frostbite and hypothermia in just three days last week, the Emergency Situations Ministry said.
Temperatures in parts of Ukraine fell to minus 16 C (3 F) during the day and minus 23 C (minus 10 F) in the night. Authorities opened 1,500 shelters to provide food and heat and closed schools and nurseries. More than 17,000 people have sought help in such shelters in the past three days, authorities said.
In Poland, at least 10 people froze to death as the cold reached minus 26 C (minus 15 F) on Monday.
Malgorzata Wozniak, a spokeswoman for Poland's Interior Ministry, told The Associated Press that elderly people and the homeless were among the dead. Police were checking unheated empty buildings for homeless people they could take to shelters.
Warsaw city authorities decided to place more than 40 heaters in the busiest city transport stops to help waiting passengers keep warm.
City authorities in the Czech capital of Prague set up tents for an estimated 3,000 homeless people. Freezing temperatures also damaged train tracks, slowing railway traffic.
In central Serbia, three people died and two more were missing, while 14 municipalities were operating under emergency decrees. Efforts to clear roads blocked by snow were hampered by strong winds and dozens of towns faced power outages.
Police said one woman froze to death in a snowstorm in a central Serbian village, while two elderly men were found dead, one in the snow outside his home. Further south, emergency crews are searching for two men in their 70s who are feared dead.
In Bulgaria, a 57-year-old man froze to death in a northwestern village and emergency decrees were declared in 25 of the country's 28 districts. In the capital of Sofia, authorities handed out hot tea and placed homeless people in emergency shelters.
Strong winds also closed down Bulgaria's main Black Sea port of Varna, while part of a major highway leading to Bulgaria and Greece from Turkey was closed after a heavy snowfall. Nearly 200 Turkish Airlines flights to and from Istanbul's Ataturk Airport were canceled, and a city sports hall was turned to a temporary shelter for some 350 homeless people.
The temperature in Turkey's province of Kars, which borders Armenia, dropped to minus 25 C on Sunday night.
The situation was similar in Romania, where reports said four people have died because of freezing weather. There, authorities sent prison inmates to shovel snow and unblock paths leading to a shelter with some 300 stray dogs and puppies.
Weather forecasts say the cold snap will continue.
"We are getting some 'real' winter this week," Croatian meteorologist Zoran Vakula said.