Astonishingly, Valery had no frostbite - not even a cold after running his 7 km maraphon at -40c. Picture: V Malkov

Valery had left his compartment to go for a cigarette, but then opened the wrong door (which should have been locked) and fell onto the track in blistering, bone-cracking cold. Suddenly as if in the worst nightmare, he found himself all alone as the warm and comfortable train receded into the distance.

If he had sat there and perished no-one would have been in the least surprised.

But hardy Siberian Valery, 42, believed to be a truck driver from Bratsk, had other ideas. Fortunately uninjured from his fall, he ran - chasing the train as it went out of sight.

And then he ran more.

He was literally running for his life, because had he remained static in this cold in such flimsy clothing, he could not have survived for long.

'When I was running I was not thinking about anything except for to get to the nearest post, station, anything,' he told Komsomolskaya Pravda.

'I don't know myself how I didn't freeze. And no, I never did winter swimming.

'Perhaps something in the body activates itself when you find yourself in an emergency situation. And, well, the station was not far, 7km.

'I'm in these places often, and I remembered about the place and the distance.'

If his 7km marathon in minus 40C was one miracle, the next was that the next station was manned. It could easily have been deserted. But a stationmaster was there in this remote outpost in Amur region, and boiled him some tea. Picture: V Malkov

If his 7km marathon in minus 40C was one miracle, the next was that the next station was manned. It could easily have been deserted. But a stationmaster was there in this remote outpost in Amur region, and boiled him some tea.

'Thanks to the chief of the station who warmed me up, and made hot tea,' said Valery.

'He was surprised, of course, when I ran in.' If ever there was an understatement.

Valery stayed the night at Richard Sorge Station - some 7,200 km east of Moscow and named after a German who spied for the USSR in the Second World War - and next morning the stationmaster halted another long distance train and he continued on his journey to Neryungri, a coal mining town in the south of the Sakha Republic, also known as Yakutia.

Astonishingly, Valery had no frostbite. Not even a cold.

An investigation was underway as to why the train door was unlocked.

Valery, meanwhile, does not say whether he will quit smoking after his unexpected adventure.