BRITISH soldiers are facing temperatures as low as -12C as they take part in Nato war games just 80 miles from Russia.
Flying in Chinook helicopters and charging round the snow-covered forests with tanks, the squaddies are ready for anything in the icy conditions of eastern Estonia.
The Sun was alongside our boys as they face the blistering cold just a stone's throw from the doorstep of Mad Vlad.
Putin has turned Russia into a pariah state thanks to his vicious invasion of Ukraine.
And the international tensions weigh heavy on the troops.
But our soldiers are standing alongside their comrades from across Europe in the face on a belligerent Russia.
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"We can see that our Estonian counterparts are worried about what's going on with Russia. But they feel we're here to help," one British tank driver told The Sun.
Temperatures in Keskpolügoon, or the Central Training Area, are down to -5C, but a blisteringly cold wind means it feels like at least -9C.
And it is expected to drop down to -12C in the coming days.
A French soldier working with Nato joked "It is warm!" as he took a puff on a cigarette.
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The camp is around an hour and a half drive from the Estonian capital Tallinn, through snow-covered fields dotted with farmhouses and Soviet-era apartment blocks.
Dense forests of fir trees provide perfect cover for camouflaged tanks and military vehicles.
On the vast military base, about the size of 15,000 football pitches, Brit troops along with other Nato forces, including the native Estonian army, have been building up for huge war games featuring heavy armour, helicopters, and rocket launchers.
Many of the soldiers have been here in the tiny Baltic nation bordering Russia for the past five months, conducting training drills and improving their battle readiness.
All of their hard work will pay off as they take part in Nato's enhanced Forward Presence Battlegroup.
They have a possible enemy nearby...they are aware they are in a risky situation.
Julien, a French army lieutenant
One British tank driver, a Lance Corporal in the King's Royal Hussars tank regiment, said the exercises demonstrate the closeness of the Nato forces.
It's also a crucial show of support for Estonia and the other former countries in the former Soviet Union, as Vladimir Putin's bloody invasion of Ukraine approaches the one-year anniversary.
The soldier continued: "We have a close bond as part of Nato now. Nato is one team, and the Estonians have got on board with that.
"They've opened their arms to us, and they're learning from us.
"If anything was to happen in the future, we'd be ready for anything."
One of his French counterparts, Julien, a lieutenant who commands a 30-person platoon, agreed.
He said: "It is important for the Estonians to see all of us from Nato here. It allows us to reassure them. To show them that Nato and the West are with them.
"They have a possible enemy nearby," he added. "They are aware they are in a risky situation."
The training, which for many of the soldiers in Keskpolügoon started back in September, hasn't been without its challenges.
One of the greatest for the British contingent has been quickly learning how to fight in the unforgiving cold of Estonia.
The British tank driver went on: "Learning to operate and fight, as well as live, in this environment is our biggest challenge."
On a day-to-day level, that means not just more thermal gear, but also learning how to handle a tank on icy roads.
"We can take the skills and drills we have learned here and take them back to the UK, or wherever we operate," he added.
"We can adapt them to any battlefield."
Tank crews can spend up to four weeks in cramped conditions, with the hatches kept shut and precious little daylight.
But the Brits have come to Estonia with some of their top equipment.
A corporal in the British army, who works as a signaller, took The Sun through the battle crew.
In a basecamp built among the frosted woods, a Bulldog FV432 armoured personnel carrier, a Panther protected patrol vehicle, and a Danish Piranha tank hulk over the surrounding soldiers.
But when they miss home, the corporal said they can go into the Bulldog and make a cup of tea.
The Danish and Estonian soldiers may be more used to the cold than their British counterparts, but that doesn't mean that they aren't learning from the UK.
Rasmus, a deputy commander in the Danish army, explained that the Brits and Danes have been cooperating in these types of missions as far back as the 1990s during the wars in the Balkans.
The highlight of the day is a thrilling staged war game between two fleets of tanks, with one chasing the other across the icy tundra of Estonia.
Denmark demonstrates its new state-of-the-art German-built Leopard 2 tanks.
Received two years ago, these exercises mark the first time they have been deployed outside of Denmark.
Effective comms are essential for military drills such as this.
The Brit signaller admitted there is a lot of pressure on people like him to make missions like this work.
If the bases can't communicate with each other, he admits, "the plans start to collapse".
Towards the end of the day, with the light quickly starting to fade, a British Chinook helicopter comes into view over the trees, sending up a cloud of snow dust that digs into the skin.
The helicopter is being used to carry military equipment across the battlelines.
A member of the Royal Engineering Squadron explains how important the Chinook is for such exercises.
He said: "The Chinook resupplies front-end engineering equipment. It means that we don't have to bring in on trucks on icy snowy days like today."
Now that the British Army has proven they work well in these exercises, they can be used to plough mines and set bridges across the combat zone.
The Royal Engineering Squadron provides the other Nato forces with mobility, counter-mobility, and survivability, stopping the enemy in its track through placing obstacles.
Britain's brave squaddies huddle around a tank in the rapidly-gathering gloom, lit cigarettes glowing in the dark.
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Two young soldiers show off their battalion flag - a white skull on a black background with the slogan "Victory or Valhalla".
"It means victory or heaven!" one explains.