Ukrainians facing 'hardest winter' yet as Russian President Vladimir Putin aggressively targets power infrastructure

Ukrainians are facing a new added deadly threat - winter. 

With houses destroyed from eight months of brutal fighting, and with Russian President Vladimir Putin now aggressively targeting power infrastructure, the cold weather will leave already vulnerable residents struggling to survive. 

In Kharkiv, which is Ukraine's second-largest city and one of the hardest hit by bombing, the outright destruction of people's homes stops you in your tracks when you first see it. But what is most disturbing is how easy it is to find buildings that have been blown apart, leaving destruction all around.

It's now the animals that keep watch over this city. Nearly half of its 1.4 million residents have left, but Natalia Pasternak never has and never will.

For eight months, she has lived in an underground maze. Curtains are clipped to concrete and there are small comforts in the coldest of places.

She's made it her wartime mission to care for all of the forgotten neighbourhood pets until their owners feel brave enough to return.

She shows Newshub where she cooks and proudly displays the "luxury" of today - at least in comparison with the power-less life she led when Russians were shelling her home. She has drinking water, as well as water for the cats and to do the washing up since her washing machine isn't working. 

But that's the least of her concerns. Like all Kharkiv residents, she is stockpiling bags of kindling and bracing for winter because firewood is the only way she can heat her place.

For another Kharkiv resident, Lina Ednarova, she can't work out why or how this happened. She has relatives just 30 kilometres away in Russia and now they are her enemies. 

Her home is blown apart and unrecognisable. Only one person is stopping her from returning and rebuilding so she can live there again - Putin.

Russian troops reached the northern suburbs of Kharkiv within 24 hours. The goal was a quick and easy win, where they'd capture a city close to the border that already spoke Russian and whose mayor opposed Ukraine President Volodymyr Zelensky. 

But the Russians got more than they signed up for. The Ukrainians were fierce in their resistance and the Russians were forced to exit - but more than 1000 civilians are said to have been killed before they did.

The number of families in need as Ukraine heads into winter is soaring. The mother of a baby born in a bomb shelter joined a line for a free bag of oats to save what money she has for heating.

"I think it will be the hardest winter in Ukraine history," one humanitarian aid worker said.