Why was Uruguayan Air Force Flight 571 survivors’ urine black in Society of Snow?

In Society of the Snow, an Oscars-tipped dramatisation of a real-life plane crash, a detail that has attracted viewers’ attention is the movie’s depiction of what happened to the survivors’ urine as they battled to stay alive in a remote, sub-zero mountain environment.

Society of the Snow: synopsis

Directed by the Spanish filmmaker JA Bayona, Society of the Snow chronicles the October 1972 crash of Uruguayan Air Force Flight 571, which came down in the Andes mountains when its pilot, Dante Héctor Lagurara, became fatally disorientated.

Incorrectly believing he had cleared the Andes, Lagurara began the plane’s descent towards its destination, the Chilean capital Santiago. The aircraft, which was in fact still in Argentina, proceeded to strike a mountain, ultimately killing 29 of the 45 people on board.

Survivors were finally rescued in late December 1972, some two and a half months after the crash.

Crash survivors’ ‘black’ urine

Half a century on, the chief reason why Flight 571 still attracts major international attention is that its surviving passengers resorted to cannibalism to avoid starvation, eating the corpses of the dead when supplies ran out.

And amid the struggle for sustenance that led the survivors to turn to cannibalism, their urine underwent a striking change in colour. Society of the Snow uses this as an arresting illustration of the strain that was placed on their malnourished bodies.

During the film, characters complain that their urine has turned “black”; indeed, we even see a shot of this unhealthily dark pee.

Why does their urine go dark in colour?

As is noted by the US’s National Institutes of Health, dark-coloured urine is a clear sign of dehydration, along with symptoms such as acute feelings of thirst, a dry mouth, dry skin, tiredness and dizziness.

What is dehydration?

Dehydration occurs when your body loses more fluid than it is taking on, causing your water content to drop below the required levels. “Water makes up over two-thirds of the healthy human body,” the UK’s National Health Service explains. “It lubricates the joints and eyes, aids digestion, flushes out waste and toxins, and keeps the skin healthy.”

In its severest cases, dehydration can lead to fainting, seizures, hypovolemic shock and kidney failure, and can be fatal.

After the Andes plane crash, the supplies of food and drink that were on the craft lasted for only about a week. While eating the corpses of other passengers chiefly prevented the 16 survivors from starving to death, it also went some way to alleviating their acute dehydration.

“Most of your fluid needs are met through the water and other beverages you drink,” the US’ Centers for Disease Control and Prevention notes, but ”you can get some fluids through the foods that you eat”.

Where to watch Society of the Snow

The Spanish-language movie, which has been shortlisted for four awards at March’s Oscars - including Best International Feature Film - was released in US cinemas on 22 December 2023. Since 4 January 2024, Society of the Snow has also been available to watch on the streaming platform Netflix.

Watch the trailer for Society of the Snow:

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