Why does Rudolph have a shiny nose?

For generations children have been fascinated with Santa's reindeer, especially the beloved Rudolph the Red-Nosed Reindeer. While adored by millions, no one has ever known exactly why Rudolph has such a bright and shiny nose. 
However, in 2012 researchers in Norway and the Netherlands set out to find out why from a scientific perspective why a reindeer's nose may glow.

The team of scientists wrote a paper about their findings entitled, "Microcirculatory investigations of nasal mucosa in reindeer Rangifer tarandus (Mammalia, Artiodactyla, Cervidae): Rudolph's nose was overheated."

In order to conclude why Rudolph has a red nose, the team of researchers used a hand-held microscope to examine a variety of nasal linings. This included: Five healthy humans, two reindeer and an individual with a nasal growth, of the non-cancerous type. The scientists used infrared technology to examine participants.

Described as a "tongue-in-cheek" investigation, the scientists found in their experiment that reindeer noses contain a higher number of blood vessels than humans and that the massive amount of exercise they do once a year while flying at rapid speeds also has an impact.

Santa's reindeer are estimated to deliver to 100 million homes and travel about 650 miles (1,000 kilometers) per second, which is no small feat.

The scientists did reportedly admit this study is not conclusive and that Rudolph may have had a cold, a hangover or an infection. (The question begs asking - one can't help but wonder based on testing results, if it is due to the number of blood vessels, why aren't the other eight reindeer sporting shiny red snouts too?)

In December 2013 a group of scientists from Sweden also decided to get to the bottom of this age-old question. They used a thermographic camera to examine things a bit more. Their study can be seen in the video above. 

"Rudolph" is listed as one of the top best-selling secular Christmas songs of all time, only second to "White Christmas". Did you know "Rudolph The Red-Nosed Reindeer" was originally written in the 1930s? It was later set to music after WWII. While Rudolph and his shiny nose are famous, his origin is lesser known.