Eighteen people have died of cold in Ukraine so far this month - most of them last weekend - as temperatures dropped below minus 10degC, the government says.
The Health Ministry said 12 people were found dead on the streets, three in their homes and three died while receiving medical treatment. Last Friday the death toll stood at six.
Night temperatures are expected to drop to -28degC in northern, central and eastern Ukraine this week, weather forecasters said on Monday.
The cold snap followed heavy snowfall which left some areas covered with as much as 53cm of snow.
Over a hundred people have been admitted to hospital with cold-related ailments and the Emergencies Ministry said it was setting up tents where people could get hot drinks and receive first aid.
Last February, as Ukraine went through its coldest winter in six years, over 130 people died of cold in the country of 45 million.