Does Facial Hair Provide Significant Thermoregulatory Advantage and Protection in the Arctic? A Case for Bearded...

Military standards favor clean shaven faces in soldiers to reinforce daily disciplinary habits and uniformity and ensure a proper seal of gas masks. In recent years, military beard policies have provided medical and religious exceptions. It has been anecdotally observed that Arctic warriors grow out their beards for added advantage in the extreme cold, but this has not been previously investigated from a thermoregulatory or frostbite injury protection perspective.

Validated mathematical models and principles of biophysics were used to predict thermal responses for a standard man with varied levels of facial hair during rest (116W) and moderately active (350W) in 3 environmental conditions, mild heat stress (24 °C; 60% relative humidity (%, RH)), cold stress (-24 °C; 70% RH), and in extreme cold (-45 °C; 75% RH). Modeling was used to compare predicted times to reach core body temperatures and skin temperatures although clean shaven (B0), and in 3 progressively increased levels of facial hair (B1, B2, and B3). Core body temperature was assessed during heat stress conditions, while skin temperatures were assessed in cold and extreme cold conditions.

Using existing thermoregulatory models, we determined that full beards compared to smooth shaven skin did not provide a significant advantage to protection of core temperature. However, finite elements modeling of thermographic changes in skin temperature predicted significant protection against frostbite injury to the face, and this was additional to protection provided by standard military balaclava wear in the Arctic.

We conclude that beards provide a lethality advantage to male soldiers operating in the cold, enhancing military exploitation of extreme cold environments.