Pfc. Sebastian Rodriguez, machine gunner, Weapons Platoon, Lima Company, 3rd Battalion, 3rd Marine Regiment, Marine Rotational Force – Darwin, fires an M240 machine gun during a night squad-attack exercise, here, May 22, 2013. (Photo by Sgt. Sarah Fiocco/U.S. Marines)

A girl looks at other children practicing on a boxing ring during an exercise session at a boxing school, in the Mare favela of Rio de Janeiro, Brazil, June 2, 2016. For many young residents the Luta Pela Paz (Fight For Peace) academy offers a glimpse of an alternative: a chance to build discipline and self-esteem through boxing and martial arts. (Photo by Nacho Doce/Reuters)

Elderly people attend an aquatic exercise at a private pool in Bangkok, Thailand, April 28, 2016. Many Thai families look after elderly relatives at a cost that countrywide adds up to just under a third of household income. The number of families facing this issue will balloon as the population ages at a rate among the fastest in Southeast Asia. (Photo by Athit Perawongmetha/Reuters)

Natalia, 51, a mother of three, serving as a combat medic in the 24th Mechanized Brigade takes part in a field training exercise in an undisclosed location in the eastern region of Ukraine, on March 18, 2025, amid the Russian invasion of Ukraine. (Photo by Roman Pilipey/AFP Photo)

U.S. Marines, left, and South Korean Marines, wearing blue headbands on their helmets, take positions after landing on the beach during the joint military combined amphibious exercise, called Ssangyong, part of the Key Resolve and Foal Eagle military exercises, in Pohang, South Korea, Saturday, March 12, 2016. North Korea said Saturday its military is ready to pre-emptively attack and “liberate” the South in its latest outburst against the annual joint military drills by the United States and South Korea. (Photo by Kim Jun-bum/Yonhap via AP Photo)

Members of the South Korean Special Weapons and Tactics team exhibit their skill during anti-terrorism exercises at a training camp on May 30, 2005 in Seoul, South Korea. (Photo by Chung Sung Jun/Getty Images)

In Jukkasjärvi, a village a few miles east of Kiruna, the proprietors of one hotel begin planning for a winter ice festival in March. That’s when they begin collecting some 5,000 tons of ice from the River Torne in order to prepare the Icehotel, the world’s coolest place to stay. Options for overnight stay include snow rooms, ice rooms, art suites, and the Northern Lights room, all of which range from about $300 to $900 per night. But the deluxe suite’s the only way to go. These rooms come with a critical amenity: heated ensuite bathrooms and saunas. Here: A man walks into a room in the Ice hotel in Jukkasjarvi, Sweden, December 16, 2015. (Photo by Ints Kalnins/Reuters)

U.S. soldiers wrestle with South Korean soldiers in a muddy ring during a joint ranger training exercise at a ranger camp near the demilitarised zone (DMZ) June 25 2003 in Paju, South Korea. (Photo by Chung Sung-Jun/Getty Images)