Are there health benefits to having a beard?

Perhaps more than any other trait, beards are perceived as a sign of gruff manliness. They visibly differentiate men from females, mask emotions, provide warmth, and shield skin from the elements. While most evolutionary theorists believe beards evolved as a display of dominance, masculinity, and aggression, what signals do they send in the modern world? And, specifically, what social information does a beard convey?