- Reindeer noses really do glow red
Whilst not all reindeer are called Rudolf, their noses really do glow red. Their noses are full of blood vessels in a very unique structure which warm up the cold air they inhale. This keeps the reindeers warm on the days where the air temperature can drop to -40 degrees Celsius in their native habitats in Siberia, North America and the Arctic.
glow noun [U] (LOOK) a red or warm look: Her face has a natural, healthy glow.
Guessing they don’t mean literally glow-in-the-dark
Glow is being used as a verb.