BRITISH troops work up a sweat in the Norwegian snow, as they prepare for war in the Arctic.

Troops on the Royal Marines’ Cold Weather Aviation Operators Course are trained to survive and operate in freezing environments, with temperatures in Norway regularly plunging below -20C.

The course provides commandos with a brutal week-long training package consisting of two days of classroom and practical demonstration lessons, followed by five nights of field training.

Troops armed with some of the best and newest kit in the Armed Forces, including enhanced night-vision goggles and overalls, practice hiding from thermal drones while training in the Arctic base.

They learn to navigate the icy landscapes and build and defend harbour areas, before being put to the ultimate test on their last night of training.

The final challenge is a survival night where comrades are given a minimal kit and must survive by building snow or brushwood shelters and wading through an icy lake.

Speaking to The Sun last month, Armed Forces Minister James Heappey explained that if Nato went to war with Russia, Britain’s main role would be fighting in Arctic conditions, which are the toughest in the world.

The elite force will spearhead Britain’s part in the largest Nato war games since the end of the Cold War.

Some 90,000 troops are due to take part in Exercise Steadfast Defender to rehearse Nato’s response to a Russian invasion.