A young visitor interacts with a baby hippopotamus swimming in its enclosure at the Berlin Zoo on January 1, 2018. Tourists and locals flocked to the zoo in the German capital on the unseasonably warm first day of the year. (Photo by Odd Andersen/AFP Photo)

Teenage girls are all steamed up these days about straight hair. The steam iron is replacing the huge rollers on which countless teens slept every night to achieve the height and curls fashionable until. The same girls endure having their hair stretched to absolute straightness on the ironing board, and then ironed to keep it that way. Unlike the roller setting, this takes teamwork. Gay Stilley, 14, goes through an ironing session with a couple of her friends at the Stilley Home in Glen Oaks, Queens, New York City on December 23, 1964. With a wary eye, Gay tries to watch the straightening process as one friend stretches her hair with a comb and another does the ironing, in the Stilley kitchen. (Photo by Marty Zimmerman/AP Photo)

An unidentified elderly woman, who was knocked over during the melee after a shot was fired in the direction of President Ford, is comforted by a passerby in San Francisco, September 23, 1975. (Photo by AP Photo)

This picture taken on January 6, 2018 shows macaque monkeys looking at a man's camera during snowfall at Wulongkou Nature Reserve in Jiyuan in China's central Henan province. (Photo by AFP Photo/China Stringer Network)

A Hindu devotee in a trance on their pilgrimage to the Batu Caves temple in Kuala Lumpur, Malaysia on January 28, 2018. Malaysian Hindu participate in the annual Hindu thanksgiving festival in which devotees subject themselves to painful rituals in a demonstration of faith and penance held in honour of Lord Murugan, Hindu in Malaysia celebrated Thaipusam begin on Jan 28 until 31 this year. (Photo by Aflo/Rex Features/Shutterstock)

Sally Rand dances on a beach in St. Petersburg, Florida, February 17, 1936. (Photo by AP Photo)

An Afghan hound arrives for the second day of the Crufts Dog Show in Birmingham, Britain March 9, 2018. The annual four-day event sees around 22,000 pedigree dogs visit the centre, before the “Best in Show” is awarded on the final day. (Photo by Darren Staples/Reuters)

Shan boys pray before they have their heads shaved in anticipation of their ordination in the Poy Song Long Ceremony at Wat Pa Pao in Chiang Mai, Thailand on April 3, 2018. Poy Sang Long (“The Festival of the Crystal Sons”) is a ceremony that marks a rite of passage among the Buddhist Shan people in Myanmar and northern Thailand. Boys between seven and fourteen years of age are ordained as Buddhist novices during a three day ceremony. Before the ceremony starts the boys have their heads shaved. (Photo by Jack Kurtz/ZUMA Wire/Rex Features/Shutterstock)