A hotel sleep tester surnamed Zhuang in Beijing

Caption from LIFE. 5:45 A.M. The mother's aunt, Catherine Prileau, tries to soothe her so that she will go to sleep and begin to forget her misery.

Original caption from LIFE. "Guarded sleep comes on prison cot with stolid and silent observer in the room throughout the night. The single electric bulb overhead burned all night."

Not published in LIFE. Early birds sleep at the track so they can be first in line at the grandstand admission windows when gates open on Derby morning.

To Sleep, Perchance to Dream ... of Acorns ...

Sinatra and Martin take a cigarette break during the recording of Sleep Warm in 1958. The album was re-released in 1963 with a much more direct title: Dean Martin Sings/Sinatra Conducts.

Frank Sinatra and Dean Martin share a light moment during their recording sessions for Sleep Warm in 1958.

'I say to my students: We all spend a big chunk of our lives dreaming—we obviously need to do it for some reason.' —Drew Dawson, Director, Centre for Sleep Research, UNISA

"Respite from horror came for Seaman Howard Wilkerson, 18, after a dreadful moment. Just before this picture was taken he had helped to remove bodies of a dead man and woman from a car which had been crushed by a falling wall. Shaken by the sight he said, "I wonder if I will ever sleep again."

Settlement house children sleep during a bus ride, 1949.

Israelis sleep in a protest tent encampment in central Tel Aviv, Israel, July 2011.

Syrians sleep at a makeshift camp near the Turkish border

Red Shirt protesters sleep before leaving their camp in central Bangkok on April 14

Anti-government protesters sleep on the streets on Aug. 29 in Bangkok, Thailand

Poor sleep habits make women more vunerable to heart disease than men..

"Dawn is a thing that poets write/ Verses about till late at night. / At daybreak, when the poets' eyes / Are closed in sleep, their neighbors rise / And put the coffee on to perk / And drink it, and go off to work." — from Richard Wilbur's "A Few Differences"

Travelers sleep as others wait inside the Greyhound Bus terminal

Caption from LIFE. "Tired child is ready to go to sleep with his head on the dining-hall table. American food is sometimes too strange for aliens. There is a kosher kitchen for orthodox Jews."

Unpublished. Willie Mays and teammates in the dugout, spring training, 1954. "Life on the Giants wouldn't be the same without Willie," Mays' friend and roommate Monte Irvin once said. "Just being around him keeps me young and full of spirit ... but I wish he'd let me sleep a little longer in the morning."

Fleeing a nightmare Syrians sleep at a makeshift camp near the Turkish border

People sleep under a mosquito net on the streets of Phnom Penh, Cambodia

Provigil, a drug manufactured by Cephalon Inc. to treat sleep disorders.

Daniel L. Everett's "Don't Sleep, There are Snakes: Life and Language in the Amazonian Jungle".

HARD LABOR: Migrant workers in Sonapur help to build Dubai's mansions and skyscrapers, yet they sleep eight to a room in labor camps

Online travel networks are helping tourist find a place to sleep free of charge.

A cross section of Green Sleep's Vimala mattress, layered for firmness.

FROG MARCH: Amphibian trackers will have to catch up on sleep at Amakhosi during the day

Caption from LIFE. "The family's day begins at dawn. In the biggest room of the shack,6 by 10 feet, 12-year-old Flavio gets himself up. While the rest of the family sleep -- the parents and five children in one bed, the other two in the crib -- Flavio puts a tin can of water on the fire and throws in some coffee. Sometimes there is hard bread to put in it. For them all, including the baby, that is breakfast."

EARLY TO RISE: From the inner-city streets of St. Louis, this "voluntary transfer student" learns the first sacrifice--sleep