Hundreds of thousands of Peruvian children returned from summer vacation this month with a new addition to their school uniform: a hat.
Education officials in the highland provinces of Cuzco and Arequipa ordered hats for their 740,000 students after a study by a Cuzco hospital found that most children had developed skin irregularities due to exposure to the sun's harmful ultraviolet rays.
Some private schools have chosen baseball caps in school colors. Public schools in Arequipa use broad-brimmed blue cloth hats. The only requirement is that children cover their heads against a midday sun that in this equatorial region can burn human skin in minutes, especially at high altitudes.
The school hat rule arises from increasing awareness of the problem across the region as local scientists better track the data and officials alert the public when levels rise.
"The amount of ultraviolet radiation received by Peru is not very different from what it was 100 years ago. The difference is that now the data is being provided to the public," said Ronald Woodman, director of Peru's Geophysics Institute.
UV radiation levels are highest between 10 a.m. and 3 p.m., when health officials say people who do not cover their skin risk developing skin cancer.
Ultraviolet radiation levels above 11 on an international scale are considered especially dangerous and it is not uncommon for them to surpass 14 in Arequipa and Cuzco, where the provincial capital is 11,166 feet (3,399 meters) above sea level.
Bolivia, whose capital of La Paz approximates Cuzco in elevation, has begun broadcasting UV alerts to the public, sometimes advising people in the highlands to avoid more than eight minutes of exposure to the midday sun.
The Peruvian authorities were spurred to action after a study by the Peruvian Dermatology Society last year detected pathologies in the skin of 73 percent of 172 randomly selected 14- and 15-year-olds in Cuzco.
Its author, Sendy Solorzano, told the AP that the abnormalities included cracked lips, skin rashes and dilated blood vessels near the skin surface.
Authorities said no reliable data was available for the region or nationwide on skin cancer.