An employee walks near a rotary dredge which works on the coal face of the Borodinsky opencast colliery, near the Siberian town of Borodino, east of Krasnoyarsk, December 9, 2014. The Borodinsky colliery, 9 km (5.6 miles) long and more than 100 meters (328 feet) deep, annually produces more than 20 million tons of coal and is considered to be the biggest opencast coal mine in Russia, according to official representatives. (Photo by Ilya Naymushin/Reuters)

A Husky dog looks on before a sled and skijoring race in the village of Kadnikovo outside Yekaterinburg, Russia, December 10, 2016. (Photo by Maxim Shemetov/Reuters)

Fire fighters, emergency service vehicles and a helicopter in Moskovsky Prospekt at the entrance to Tekhnologichesky Institut station of the St Petersburg metro in the aftermath of an explosion which occurred in a train at 14:40 Moscow timeon April 3, 2017. (Photo by Peter Kovalev/TASS)

A participant has her body painted before a local bodybuilding and fitness championship in the Siberian city of Krasnoyarsk, Russia, March 5, 2016. (Photo by Ilya Naymushin/Reuters)

A cat sits in front of a retro car owned by retired mechanic Mikhail Krasinets at an open-air museum of Soviet-era vehicles in the village of Chernousovo, Tula region, Russia on September 27, 2018. In the remote village of Chernousovo, retired mechanic Mikhail Krasinets tends to more than 300 ramshackle, Soviet-era cars, remnants of a once vibrant auto industry that crumbled with the fall of the Soviet Union. (Photo by Maxim Shemetov/Reuters)

Yakutsk, with a population of around 270,000, holds its own title: that of the coldest city on Earth. Here: Frost-encrusted house in the city centre. (Photo by Amos Chapple/Courtesy Images/RFE/RL)

These Northern Lights “rainbows” have turned the sky greener than the Earth below. Vitaly Istomin, 26, spent several nights in freezing conditions under the stars in northern Russia’s Khibiny Mountains to capture the aurora’s “rainbows”. (Photo by Vitaly Istomin/Caters News Agency)

A girl in a swimsuit participates in the BoogelWoogel alpine carnival at the Rosa Khutor Alpine Resort in Krasnaya Polyana, Sochi, Russia on March 31, 2018. (Photo by Artur Lebedev/TASS)