A cat wears a “Tsunagaru Col” gadget next to a smart phone displaying the connected app, at the Anicall Corp booth during the Wearable Device Technology Expo in Tokyo January 14, 2015. The gadget (“Tsunagaru” means connection) for animals tracks information about pets, such as the location and other animals the pet might be interacting with, with the purpose of providing “social networking” for animals. The expo runs until January 16 as a part of Japan's largest electronic exhibition expected to attract around 77,000 visitors, according to organisers. (Photo by Yuya Shino/Reuters)

Sailors stand on the deck as the USS New York as it passes the Statue of Liberty during the start of Fleet Week May 25, 2011 in New York City. Fleet week, which has been held in New York City since 1984, celebrates the U.S. Navy and Marines Corps with a week of ship visitations and military demonstrations. Fleet Week concludes on Memorial Day with a military flyover to honor those killed while serving in the military. (Photo by Spencer Platt/Getty Images)

Syrian civil defence volunteers, known as the White Helmets, rescue a boy from the rubble following a reported barrel bomb attack on the Bab al- Nairab neighbourhood of the northern Syrian city of Aleppo on November 24, 2016. (Photo by Ameer Alhalbi/AFP Photo)

A volunteer puts a banknote on remains for luck during a mass exhumation at Poh Teck Tung Foundation Cemetery in Samut Sakhon province, Thailand November 3, 2015. Human remains from 3,890 unclaimed bodies have been dug out of graves to be cleaned and put into storage in a warehouse before being cremated, in order to make room for further unidentified corpses. (Photo by Athit Perawongmetha/Reuters)

Firefighters and volunteers work to extinguish a wildfire in Krieza, on Evia Island, Greece, on Tuesday, July 30, 2024. A strong wind in the Aegean Sea is increasing wildfire risks, while parts of the mainland will see heat of 43C by the end of the week. (Photo by Nick Paleologos/Bloomberg)

In this photo taken on July 19, 2014, a man looks at an excavation as an A.R.M.H., Association for the Recovery of Historical Memory, volunteer digs on the search for the body of Perfecto de Dios, in a hidden grave in Chaherrero, Spain. Across Spain, volunteer teams of archeologists, anthropologists and forensic scientists head out every year on expeditions to dig for suspected mass graves – a legacy of Spain's fascist past during the time of General Francisco Franco. (Photo by Daniel Ochoa de Olza/AP Photo)

A volunteer photographs a woman as she kisses a volunteer wearing a condom costume during marking the International Condom Day in Kiev, Ukraine, 13 February 2015. The event was organized to promote and create awareness towards “Safe s*x” and the use of condoms to control and prevent Human Immunodeficiency Virus (HIV) and other sexually transmitted diseases on the occasion of the International Condom day. (Photo by Roman Pilipey/EPA)

A volunteer poses for a photograph with a snowman depicting the Beijing Winter Olympics mascot Bing Dwen Dwen at National Biathlon Centre in Zhangjiakou, China on February 13, 2022. (Photo by Kim Hong-Ji/Reuters)