Standing by a makeshift stove at the bottom of a bitterly-cold ditch, the Ukrainian troops enjoyed a quick tea break.
Suddenly there was a loud whistle and a crack as a Russian artillery round flew overhead and exploded in a field behind them.
The soldiers barely flinched, hardened by months of war. Instead, their focus was on staying warm.
One of them even carried on calmly cutting into a plastic bottle.
The water inside had frozen solid as temperatures on the frontline plunged below zero.
Peeling away the plastic, he plonked the giant, bottle-shaped ice cube into a pan to melt.
Then came a second round, this one much closer, smashing into a road above them with a punishing crash.
"That was too near," said a fellow soldier, before taking a sip of tea from a tin mug.
A Sky News team also in the large ditch had hit the ground at the sound of the first blast and was then ushered towards better cover after the second one - along with the troops.
This is the daily reality for Ukrainian soldiers holding defensive positions in trenches close to the frontline town of Bakhmut in the Donetsk region of eastern Ukraine.
Russian forces appear determined to try to take the town after suffering humiliating defeats in other parts of the country.
It has made the Battle for Bakhmut one of the fiercest of the war - described as a "meat grinder" because of the scale of the casualties.
One soldier, a company commander who asked to go by his first name Maks, vowed the Russians would never succeed.
"They will throw up more meat and we will destroy it," he said. "They will launch rockets, but we will hide and then destroy them. They have no chance."
In a trip on Monday that was cut short by the artillery attack, Maks and other members of a battalion in Ukraine's 24th King Danylo Brigade showed Sky News around a line of trenches they were digging as part of efforts to help defend Bakhmut.
It is tough work even without the threat of enemy fire as soldiers must also battle the elements.
Armed with a shovel, a soldier called Serhii cut away at chunks of earth as he made a square-shaped trench.
"We are on our land, we need to defend our land," he said, his breath frosty. "It's hard but it's needed."
Signs of winter were all around - a rucksack and bedding, layered with frost; specks of white on the hard earth; and a green, woollen hat with a frosted covering, hanging off the bare branch of a tree.
These soldiers must fight, eat and sleep in the cold - but they know the Russians must endure the same, many with worse protective clothing.
Temperatures will likely drop even to minus 30 by January and February.
Analysts have said both sides may seek to slow or even pause the fighting when conditions become too harsh. But Ukrainians say they will push on as they have no other choice.
"We will fight - how can we stop?" said Orest, the battalion commander.
Fighting will be at 'reduced tempo for months'
Ukraine's armed forces have lost up to 13,000 soldiers since Russian invasion
Ukrainian and western officials say Wagner, the Russian private military company, has sent large numbers of mercenaries - including convicted criminals released on condition they fight - to launch wave after wave of assaults against Ukrainian positions in Bakhmut.
Conventional Russian forces, withdrawn from the southern city of Kherson in the face of a Ukrainian counter-offensive last month, have also been added to the fight in recent days, increasing the pressure on Ukrainian lines.
Asked whether the Russians would capture the town, Orest said: "No …we will stop them."
But Ukrainian troops are paying a heavy price as well.
The commander showed us where Russian rounds over the past two days had crashed into a field close to where his men had been digging, killing one of his soldiers.
This is meant to be a defensive line, set slightly back from the frontline action.
Orest said he has lost a total of seven troops in the past month, mainly doing assaults against Russian positions. He said the nearest Russian point is just over a mile away.
The change of season means there are no longer leaves on the trees, providing top cover from drones, sent to scout targets for artillery to strike - a new peril for both sides.
There is a constant threat of incoming fire - as we later discovered during the tea break.
That artillery attack went on for almost half an hour.
Each time a round struck, the ground shook - a terrifying experience, even from where we had been able to shelter.
Yet this deadly hazard is something the soldiers have grown almost immune to.
After a while, the commander said it was safe to leave.
We made a scramble up a bank of the ditch to our vehicle and sped off. For the troops, they stayed put, dug in for the winter war.
(c) Sky News 2022: Ukrainians fighting Russian mercenaries and plummeting temperatures in the Battle for Bakhmut