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)

This year's Republican National Convention and Democratic National Convention both saw passionate delegates in outrageous costumes – but that's where the similarities mostly end. Reuters photographer Jim Young gives a look at what it's like to be on the convention floor and talks to the delegates who make the conventions memorable. (Photo by Jim Young/Reuters)

This long exposure picture shows vehicles on roads during rush hour on the eve of the National Day holidays in Shanghai on September 30, 2014. According to local media, police checkpoints will be set up at highways, elevated roads and business hubs to tackle drunk driving during the National Day holiday. (Photo by Johannes Eisele/AFP Photo)

A protester in an Elmo mask dances during the Justice for George Floyd Philadelphia Protest on Saturday, May 30, 2020. Demonstrators took to the streets across the United States to protest the death of Floyd, a black man who was killed in police custody in Minneapolis on May 25. (Photo by Matt Rourke/AP Photo)

A jogger is seen running at Hampstead Heath with London in the background on June 1, 2021. Britain sees temperatures increasing for the second day in a row after the mercury hit 25C (77 Fahrenheit) for the warmest day of the year so far on Bank Holiday Monday. (Photo by Joshua Bratt/London News Pictures)

An empty Turcot Interchange is shown in Montreal, Saturday, January 9, 2021, as the Quebec government imposed a curfew to help stop the spread of COVID-19 starting at 8 p.m until 5 a.m and lasting until Feb. 8. (Photo by Graham Hughes/The Canadian Press via AP Photo)

Police officers look on as they stand guard to secure the area where Dutch celebrity crime reporter Peter R. de Vries, known for his reporting on some of the most renowned criminals in the Netherlands, was reportedly shot and seriously injured, in Amsterdam, Netherlands, July 6, 2021. (Photo by Eva Plevier/Reuters)

A leopard attacks a forest guard at Prakash Nagar village near Salugara on the outskirts of Siliguri on July 19, 2011. Six people were mauled by the leopard after the feline strayed into the village area before it was caught by forestry department officials. Forest officials made several attempt to tranquilised the full grown leopard that was wandering through a part of the densely populated city when curious crowds startled the animal, a wildlife official said. (Photo by Diptendu Dutta/AFP Photo)