Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/AP Photo)

Free Syrian Army fighters stand near an ambulance on the eastern edge of the northern Syrian town of al-Bab, Syria, February 27, 2017. (Photo by Khalil Ashawi/Reuters)

A man cries as he carries his daughter while walking from an Islamic State-controlled part of Mosul towards Iraqi special forces soldiers during a battle in Mosul, Iraq March 4, 2017. Reuters Photographer Goran Tomasevic: “Both screaming in terror, a father and the young daughter he cradled in his arm fled through the rubble-strewn streets of Wadi Hajar, transformed in a flash into a battleground between Islamic State fighters and Iraqi special forces. They and their neighbours – some wearing rubber sandals, some barefoot – were running from an IS counter-attack in this part of Mosul, dodging gunfire as the militants closed in”. (Photo by Goran Tomasevic/Reuters)

Faithful wearing face mask pray during the Arafah prayer ceremony ahead of Eid al-Adha, at the Tehran university’s mosque in Tehran, Iran, 30 July 2020. Iran will not hold the Eid al-Adha prayers and ceremonies over the coronavirus (COVID-19) crisis in the country. (Photo by Abedin Taherkenareh/EPA/EFE)

Devotees wearing personal protective equipment (PPE), carry a chariot of Pachali Bhairab amid the spread of coronavirus disease (COVID-19), in Kathmandu, Nepal on October 21, 2020. (Photo by Navesh Chitrakar/Reuters)

A woman wearing a traditional costume attends the celebrations marking the National Flag Day and the Day of Kyrgyz national “Ak-kalpak” hat at the central Ala-Too Square in Bishkek on March 4, 2021. (Photo by Vyacheslav Oseledko/AFP Photo)

Shortlist, open competition, lifestyle. Healing Vibes – the hot springs of Bagno Vignoni in Italy flow out at a temperature of about 49°C. They were appreciated by the Romans for their healing powers, and have been used as therapeutic treatments since the 12th century, under Emperor Federico II. (Photo by Stefano Butturini/Sony World Photography Awards)

Erica Daly, a District Nurse Team Leader at Mersey Care NHS, stands in front of the “Liver Bird Wings”, an artwork by Paul Curtis on a wall within Liverpool's Baltic Triangle on April 29, 2020. (Photo by Peter Byrne/PA Images via Getty Images)