The Short Answer: Probably but we still can’t say with 100% certainty.
The Long Answer: From experience, yes beards help keep the wearer warmer in the cold. From an evolutionary perspective, it makes perfect sense that hunters would develop some sort of defense mechanism for the winter. From a scientific perspective, however, we cannot conclusively say that beards combat the cold.
A 2012 Chinese study determined that men without upper lip hair lost more body heat than their mustached peers. This study did not research beards and their trends and so we can only extrapolate the data and findings which means we are no longer in strictly scientific territory. Expert dermatologists readily promote the idea that a beard is an effective defender against the elements but they base their reasoning on logic and reason as opposed to lap experiments and research.
One researcher from the University of Ottawa, Pete Hickey, conducted an unofficial experiment on himself. He shaved half of his beard and then did some winter activities to see if his bearded half felt warmer. Among his conclusions were that the bearded half of his head felt heavier and faced more wind resistance, meaning he had to keep adjusting his neck posture. He also concluded that the bearded side of his face felt warmer.
If you know of any other major study conducted regarding facial hair and body temperature, please let us know. In the meantime, the only way to really know if beards actually keep you warm is to grow one yourself and see what the hype’s about!