Patches on giraffes play a surprising role

Staying cool in hot weather is central to the survival of most giraffes, and this function is believed to be greatly aided by one of their most noticeable features—patches.

According to Smithsonian.com, "The dark patches on a giraffe's body hide an intricate network of blood vessels and glands. These allow blood to flow through them, releasing heat and cooling the body."

As such, these pigmented areas have been called their "thermal window."

See more photos of the fascinating creature:

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Meet these friendly giraffes
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Meet these friendly giraffes
(FILES) - Picture taken on Febuary 7, 2014 shows a perfectly healthy young giraffe named Marius who was shot dead and autopsied in the presence of visitors to the gardens at Copenhagen zoo on Febuary 9, 2014 despite an online petition to save it signed by thousands of animal lovers. Marius, an 18-month-old giraffe, was put down with a bolt gun early on Sunday, zoo spokesman Tobias Stenbaek Bro confirmed. KELD NAVNTOFT/AFP/Getty Images
A picture taken on April 20, 2014 shows five-day-old Rothschild giraffe Jabulani at the Zoo-Aquarium in Madrid. AFP PHOTO / DANI POZO (Photo credit should read DANI POZO/AFP/Getty Images)
The young Rothschild Giraffe Jamal runs at the zoo in Leipzig, eastern Germany, on February 21, 2014. The giraffe bull born on January 18, 2014 was baptized Jamal, meaning 'Beauty'. AFP PHOTO / DPA/ SEBASTIAN WILLNOW GERMANY OUT (Photo credit should read SEBASTIAN WILLNOW/AFP/Getty Images)
Rothschild's giraffe baby Katja is pictured at the Opelzoo in Kronberg, Germany on January 7, 2014. The animal was born on January 2, 2014. AFP PHOTO / DPA / FRANK RUMPENHORST +++ GERMANY OUT (Photo credit should read FRANK RUMPENHORST/AFP/Getty Images)
Female Ugandan giraffe 'Lotti' chews on branches at her enclosure at Berlin's Tierpark zoo April 19, 2013. Rothschild's giraffe is one of the most endangered giraffe subspecies with only a few hundred members in the wild. AFP PHOTO / JOHN MACDOUGALL (Photo credit should read JOHN MACDOUGALL/AFP/Getty Images)
KENYA - 2013/10/25: Endangered Rothschild's giraffes (Giraffa camelopardalis rothschildi) at Lake Nakuru National Park in the Great Rift Valley in Kenya. (Photo by Wolfgang Kaehler/LightRocket via Getty Images)
A picture taken on April 20, 2014 shows five-day-old Rothschild giraffe Jabulani at the Zoo-Aquarium in Madrid. AFP PHOTO / DANI POZO (Photo credit should read DANI POZO/AFP/Getty Images)
A young male Rothschild giraffe is presented at the zoo in the eastern German city of Leipzig on March 5, 2012. The giraffe, born on February 22, 2012 belongs to the most endangered giraffe subspecies with only a few hundred members in the wild. AFP PHOTO / PETER ENDIG GERMANY OUT (Photo credit should read PETER ENDIG/AFP/Getty Images)
Giraffe Manor, Rothschild's Giraffe, Kenya (Photo by: EyeOn/UIG via Getty Images)
Ugandan giraffe 'Shahni' licks her 20 days old daughter on September 15, 2010 in their enclosure at the zoo in Hanover, central Germany. The baby giraffe is the 50th giraffe born at the zoo. In the wild, Ugandan giraffes also known as Rothschild giraffes are an endangered species. AFP PHOTO HOLGER HOLLEMANN GERMANY OUT (Photo credit should read HOLGER HOLLEMANN/AFP/Getty Images)
Rothschild Giraffe, Giraffe Manor, Nairobi, Kenya, Africa (Photo by: EyeOn/UIG via Getty Images)
CHESTER, UNITED KINGDOM - JANUARY 30: Margaret, the 10-day-old Giraffe, is bottle fed by Chester Zoo keeper Tim Rowlands on January 30, 2008, in Chester, England. Margaret is the first Rothschild giraffe born at the zoo and is being hand reared after having difficulty suckling from her mother. Margaret, who is named after keeper Tim's mother, already measures 1.2m (Photo by Christopher Furlong/Getty Images)
Rothschild Giraffe, Giraffe Manor, Nairobi, Kenya, Africa (Photo by: EyeOn/UIG via Getty Images)
(FILES) - Picture taken on Febuary 7, 2014 shows a perfectly healthy young giraffe named Marius who was shot dead and autopsied in the presence of visitors to the gardens at Copenhagen zoo on Febuary 9, 2014 despite an online petition to save it signed by thousands of animal lovers. Marius, an 18-month-old giraffe, was put down with a bolt gun early on Sunday, zoo spokesman Tobias Stenbaek Bro confirmed. AFP PHOTO / SCANPIX DENMARK / KASPER PALSNOV +++ DENMARK OUT +++ (Photo credit should read KELD NAVNTOFT/AFP/Getty Images)
(FILES) - Picture taken on Febuary 7, 2014 shows a perfectly healthy young giraffe named Marius who was shot dead and autopsied in the presence of visitors to the gardens at Copenhagen zoo on Febuary 9, 2014 despite an online petition to save it signed by thousands of animal lovers. Marius, an 18-month-old giraffe, was put down with a bolt gun early on Sunday, zoo spokesman Tobias Stenbaek Bro confirmed. AFP PHOTO / SCANPIX DENMARK / KASPER PALSNOV +++ DENMARK OUT +++ (Photo credit should read KELD NAVNTOFT/AFP/Getty Images)
COPENHAGEN, DENMARK - FEBRUARY 8: An 18-month-old giraffe named Marius (Rear 2nd L) will be slept on Sunday before Copenhagen zoo to kill surplus young giraffe and feed him to the lions in Copenhagen, Denmark, on February 8, 2014. Animal rights campaigners in Denmark are trying to save a healthy young giraffe at Copenhagen Zoo from being destroyed. (Photo by Irfan Cemiloglu/Anadolu Agency/Getty Images)
COPENHAGEN, DENMARK - FEBRUARY 8: An 18-month-old giraffe named Marius (R) will be slept on Sunday before Copenhagen zoo to kill surplus young giraffe and feed him to the lions in Copenhagen, Denmark, on February 8, 2014. Animal rights campaigners in Denmark are trying to save a healthy young giraffe at Copenhagen Zoo from being destroyed. (Photo by Irfan Cemiloglu/Anadolu Agency/Getty Images)
COPENHAGEN, DENMARK - FEBRUARY 8: An 18-month-old giraffe named Marius (C) will be slept on Sunday before Copenhagen zoo to kill surplus young giraffe and feed him to the lions in Copenhagen, Denmark, on February 8, 2014. Animal rights campaigners in Denmark are trying to save a healthy young giraffe at Copenhagen Zoo from being destroyed. (Photo by Irfan Cemiloglu/Anadolu Agency/Getty Images)
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Interestingly, researchers are unsure if giraffes perspire or not because, though they have sweat glands, some have argued that they are non-functioning remnants from ancestors.

However, the fact that these glands are bigger under the patches indicates that they could play some role in cooling the animals.

Smithsonian points out that giraffes' long, slender necks provide a larger surface area for more patches, increasing the opportunities "...for giving off heat."

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