A bunker at aformer Swiss artillery fortress called Heldsberg stands near the town of St. Margareten, Switzerland March 22, 2015. Heldsberg fortress, located on the Swiss-Austrian border near the River Rhine and Lake Constance was built from 1938 to 1940 and remained in military use until 1992. Since 1993 it is open to the public as Fortress Museum Heldsberg. (Photo by Arnd Wiegmann/Reuters)

Participants of the 77th edition of the annual Christmas swimming 'Coupe de Noel' jump into the waters of Lake Geneva, in Geneva, Switzerland, 20 December 2015. More than 1,540 men and women braved the water temperature of just 8 degrees Celsius as they swam a 120 meters distance at the traditional Christmas swimming in Geneva. (Photo by Salvatore Di Nolfi/EPA)

A model presents a creation by designer Alexis Mabille as part of his Haute Couture Spring/Summer 2020 collection show in Paris, France, January 21, 2020. (Photo by Francois Lenoir/Reuters)

U.S. President Donald Trump holds news conference on the coronavirus outbreak at the White House in Washington, U.S., February 26, 2020. (Photo by Carlos Barria/Reuters)

Paramedics wearing protective suits amid fears of coronavirus outbreak check on a man who collapsed outside a clinic in Jakarta, Indonesia, Thursday, March 26, 2020. It's not immediately clear what caused the man to collapse. The U.S. Embassy in Indonesia has ordered the departure of employees' family members under the age of 21 from its missions in the country where new COVID-19 patients have surged in the past week with high fatality. (Photo by Muchlis Akbar/AP Photo)

Artists perform as people watch from the safety of their cars, during the Art Parking drive-in festival in Prague, Czech Republic, Sunday, April 26, 2020. Artists in Czech Republic are finding different ways to perform as regular theaters remain closed in an effort to stem the spread of coronavirus. (Photo by Petr David Josek/AP Photo)

Mike Bennett wears a Patriot face mask on his mouth as a preventive measure against the spread of COVID-19 while skateboarding with his dog amid the novel coronavirus pandemic in Huntington Beach, California on April 25, 2020. Orange County is the only county in the area where beaches remain open, lifeguards in Huntington Beach expect tens of thousands of people to flock the beach this weekend due to the heat wave. Lifeguards and law enforcement are patrolling the beach to make sure people are keeping their distance. (Photo by Apu Gomes/AFP Photo)

A man wears a protective face mask as he walks along the main market in downtown after the government eased the restrictions on movement aimed at containing the spread of the coronavirus disease (COVID-19), in Amman, Jordan on April 29, 2020. (Photo by Muhammad Hamed/Reuters)