Dozens of people have died as freezing weather has gripped much of Europe and the eastern USA.
In Poland, 10 people have died as snow and ice covered the country – and much of the rest of the continent.
Other deaths were reported in Russia, Italy, the Ukraine and the Czech Republic.
Temperatures in Russia have plummeted to below -40 Centigrade.
Aid workers at French charity Medecins Sans Frontieres expressed concerned about thousands of vulnerable people across the continent ‘stuck in undignified conditions’.
The group was referring to thousands of refugees sheltering in Greece and Serbia, where temperatures are -20C.
Refugees sleeping out most at risk
Many of the refugees are children and teenagers fleeing Afghanistan, Pakistan, Iraq and Syria.
In Greece, many islands are snowbound and thousands of refugees are seeking shelter in heated accommodation.
Elsewhere, airports have closed, rivers frozen over and pupils have been told to stay away from schools.
In the US, several deaths were reported as a snow and ice storm moved across the east of the country. The deaths were blamed on cars colliding in the snow as police attended more than 1,000 crashes in North Carolina and Virginia.
More than 20 inches of snow fell near Boston, Massachusetts, while many other places reported snowfalls of 10 or more inches.
Power outages also affected thousands of homes.
Although the weather has slightly improved over recent days, the cold snap is expected to return at the weekend.
More snow on the way, say meteorologists
Forecasters say freezing temperatures and cold winds will hit Europe with warnings of disruption and more snow in many regions.
Meanwhile, scientists blame the deep freeze on the melting Arctic ice cap, with warmer weather disrupting the jet stream in the upper atmosphere.
As the jet stream strengthens and weakens, colder and warmer weather fronts are pulled across Europe and the USA.
“We are now in uncharted territory,” said Prof Jennifer Francis, an Arctic climate expert at Rutgers University in the USA. “These rapid changes in the Arctic are affecting weather patterns everywhere now.”
She explained adverse weather patterns could make many places uninhabitable by 2100 unless drastic action to control climate change is taken by governments.