An Exmoor wild goat silhouetted in the sky over the Bristol Channel at the valley of the Rocks, North Devon, as the UK's heat wave continues on July 19, 2018. (Photo by Paul Silver/South West News Service)

A U.S. Air Force B-1B Lancer bomber sits on the runway at Anderson Air Force Base, Guam July 18, 2017. (Photo by Airman 1st Class Christopher Quail/Reuters/U.S. Air Force)

A herd of elephants cross a road that passes through the flooded Kaziranga National Park in the northeastern state of Assam, India, July 12, 2017. (Photo by Anuwar Hazarika/Reuters)

Revellers dressed as zombies take part in an enactment of the running of the bulls a day before the start of the San Fermin festival in Pamplona, northern Spain, July 5, 2016. (Photo by Eloy Alonso/Reuters)

Participants play with water guns during the Sinchon Water Gun Festival in Seoul, South Korea, July 9, 2016. (Photo by Kim Hong-Ji/Reuters)

Revellers take part in the annual “Naval Battle” of Vallecas during the Virgen del Carmen Festival in Madrid, Spain July 17, 2016. (Photo by Javier Barbancho/Reuters)

Law enforcement officers clash with protesters, Wednesday, July 20, 2016, in Cleveland, during the third day of the Republican convention. (Photo by John Minchillo/AP Photo)

Attendees dressed as Poison Ivy and Harley Quinn arrive for opening day of the annual Comic-Con International in San Diego, California, United States July 21, 2016. (Photo by Mike Blake/Reuters)