A psychologist talks to a member of the medical personnel in the chill-out area of the CHU de Liege hospital, amid the coronavirus disease (COVID-19) outbreak, in Liege, Belgium May 6, 2020. REUTERS/Yves Herman

A psychologist talks to a member of the medical personnel in the chill-out area of the CHU de Liege hospital, amid the coronavirus disease (COVID-19) outbreak, in Liege, Belgium May 6, 2020. REUTERS/Yves Herman

A physiotherapist massages a member of the medical personnel in the chill-out area of the CHU de Liege hospital, amid the coronavirus disease (COVID-19) outbreak, in Liege, Belgium May 6, 2020. REUTERS/Yves Herman

A psychologist talks to a member of the medical personnel in the chill-out area of the CHU de Liege hospital, amid the coronavirus disease (COVID-19) outbreak, in Liege, Belgium May 6, 2020. REUTERS/Yves Herman

A physiotherapist massages a member of the medical personnel in the chill-out area of the CHU de Liege hospital, amid the coronavirus disease (COVID-19) outbreak, in Liege, Belgium May 6, 2020. REUTERS/Yves Herman

A physiotherapist massages a member of the medical personnel in the chill-out area of the CHU de Liege hospital, amid the coronavirus disease (COVID-19) outbreak, in Liege, Belgium May 6, 2020. REUTERS/Yves Herman

A physiotherapist massages a member of the medical personnel in the chill-out area of the CHU de Liege hospital, amid the coronavirus disease (COVID-19) outbreak, in Liege, Belgium May 6, 2020. REUTERS/Yves Herman

Fresh french fries are seen at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Fresh french fries are seen at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Fresh french fries are seen at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Fresh french fries are seen at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Fresh french fries are seen at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

A worker with a protective mask looks at a bag of fresh french fries at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Potatoes are seen at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Potatoes are seen at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Potatoes are seen at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Fresh french fries are seen at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Potatoes are seen at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the coronavirus disease (COVID-19) outbreak, in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

A worker with a protective face mask checks a machine at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the outbreak of the coronavirus disease (COVID-19) in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

A worker with a protective face mask checks a machine at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the outbreak of the coronavirus disease (COVID-19) in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

A worker with a protective face mask checks a machine at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the outbreak of the coronavirus disease (COVID-19) in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

A worker with a protective face mask checks a machine at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the outbreak of the coronavirus disease (COVID-19) in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Workers with protective face masks check machines at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the outbreak of the coronavirus disease (COVID-19) in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Workers with protective face masks check machines at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the outbreak of the coronavirus disease (COVID-19) in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

A worker with a protective face mask checks a machine at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the outbreak of the coronavirus disease (COVID-19) in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

A worker with a protective face mask checks a machine at Mydibel Group factory, a manufacturer of chilled, frozen and dehydrated potato products, amid the outbreak of the coronavirus disease (COVID-19) in Mouscron, Belgium April 29, 2020. REUTERS/Yves Herman

Sugar beets covered in snow at a processing facility in East Grand Forks, Minnesota, U.S., November 22, 2019. Due to a wet summer and early frost, sugar beet farmers were forced to leave hundreds of acres of sugar beet crop unharvested, a hard hit for the US agriculture industry already experiencing a difficult few years. Picture taken November 22, 2019. REUTERS/Nicholas Pfosi

Sugar beets covered in snow at a processing facility in East Grand Forks, Minnesota, U.S., November 22, 2019. Due to a wet summer and early frost, sugar beet farmers were forced to leave hundreds of acres of sugar beet crop unharvested, a hard hit for the US agriculture industry already experiencing a difficult few years. Picture taken November 22, 2019. REUTERS/Nicholas Pfosi

Sugar beets covered in snow at a processing facility in East Grand Forks, Minnesota, U.S., November 22, 2019. Due to a wet summer and early frost, sugar beet farmers were forced to leave hundreds of acres of sugar beet crop unharvested, a hard hit for the US agriculture industry already experiencing a difficult few years. Picture taken November 22, 2019. REUTERS/Nicholas Pfosi

Partly frozen Svisloch river is seen in Minsk, Belarus November 26, 2019. REUTERS/Vasily Fedosenko

Ducks swim in Svisloch river in Minsk, Belarus November 26, 2019. REUTERS/Vasily Fedosenko

A patch of snow is covered for tourists to use with slides later in the season on the Tsanfleuron Glacier near Les Diablerets in Switzerland, September 13, 2019. Picture taken September 13, 2019. REUTERS/Denis Balibouse

The Aurora Borealis is visible from a plane at 37,000 feet above the Labrador Sea and the North Atlantic Ocean between Canada and Greenland, November 22, 2019. Picture taken November 22, 2019. REUTERS/Jim Urquhart

The Aurora Borealis is visible from a plane at 37,000 feet above the Labrador Sea and the North Atlantic Ocean between Canada and Greenland, November 22, 2019. Picture taken November 22, 2019. REUTERS/Jim Urquhart

Car is seen covered with snow in village of Iselsberg, Austria, November 14, 2019. REUTERS/Antonio Bronic

Snow drifts are seen on a summit near the village of Seefeld, Austria, November 14, 2019 REUTERS/Angelika Warmuth

Larches stand in the snow near the village of Seefeld, Austria, November 14, 2019 REUTERS/Angelika Warmuth

Larches stand in the snow near the village of Seefeld, Austria, November 14, 2019 REUTERS/Angelika Warmuth

Larches stand in the snow near the village of Seefeld, Austria, November 14, 2019 REUTERS/Angelika Warmuth

Snow lies on a deck chair in a garden near the village of Seefeld, Austria, November 14, 2019 REUTERS/Angelika Warmuth

The road along the Russian - Norway border is seen in Pasvik valley, Finnmark county, Norway, October 23, 2019. REUTERS/Maxim Shemetov

A road sign lies on the grass in Kirkenes, Norway, October 26, 2019. REUTERS/Maxim Shemetov

People ride on horses in front of the snow-covered mountains in the central Swiss Alps near Studen, Switzerland November 9, 2019. REUTERS/Arnd Wiegmann

Snow covered farm fields make a quit-like patchwork near Bridgewater, South Dakota, U.S. November 8, 2019. REUTERS/Jim Urquhart

An observational tower overlooks the Norway-Russia border from the Norwegian side in Pasvik valley, Finnmark county, Norway, October 23, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

A view shows a World War Two monument To The Defenders of Soviet Arctic, which is located in Murmansk, Russia, October 27, 2019. REUTERS/Maxim Shemetov SEARCH "NORWAY-RUSSIA BORDER" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES.

A wooden boat is seen on a bank of frozen Varzuga river in the village of Varzuga in Murmansk region, Russia October 31, 2019. REUTERS/Maxim Shemetov

Power transmission lines are seen on a frosty day outside the town of Monchegorsk in Murmansk region, Russia October 31, 2019. REUTERS/Maxim Shemetov

Frozen White Sea is seen outside the town of Kandalaksha in Murmansk region, Russia October 31, 2019. REUTERS/Maxim Shemetov

Ducks swim in a lake in a park in Saint Petersburg, Russia October 29, 2019. REUTERS/Anton Vaganov

A view shows a giant foot print, which was trodden on the ground following an early snowfall in the Siberian city of Omsk, Russia October 18, 2019. REUTERS/Alexey Malgavko TPX IMAGES OF THE DAY

A paraglider flies above the Bossons glacier in the Mont-Blanc massif on a sunny autumn day in Chamonix, France October 8, 2019. REUTERS/Denis Balibouse

The Bossons glacier in the Mont-Blanc massif is pictured on a sunny autumn day in Chamonix, France October 8, 2019. REUTERS/Denis Balibouse

The sun lights larch trees in the Mont-Blanc massif on a sunny autumn day in Chamonix, France October 8, 2019. REUTERS/Denis Balibouse

Snow is protected with fabric to prevent it from melting on a ski slope in a glacier ski resort near the village of St. Leonhard im Pitztal, Austria, July 6, 2019. REUTERS/Lisi Niesner

A segment of the Planpincieux glacier is seen on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 27, 2019. REUTERS/Yara Nardi

A general view of the Italian side of the Mont Blanc massif area, with the Planpincieux glacier, Aosta, Italy, September 27, 2019. REUTERS/Yara Nardi

A segment of the Planpincieux glacier is seen on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 27, 2019. REUTERS/Yara Nardi

A segment of the Planpincieux glacier is seen on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 27, 2019. REUTERS/Yara Nardi

A segment of the Planpincieux glacier is seen on the Italian side of the Mont Blanc massif area of Planpincieux, Aosta, Italy, September 27, 2019. REUTERS/Yara Nardi