As a matter of fact, my Beard makes me hot all year long. So says Wendy at least. As summer approaches in the northern hemisphere, the most-asked question I hear regarding my Beard is whether I'm going to shave it off because of the warmer weather. Some people like to retort with something clever like, "Manliness knows no season" (with which I fully agree). My answer is a blank expression with direct, extended eye contact followed by..."No."
I can understand why people who have never had a Beard would ask this question. It only makes sense that having all that extra hair on your face would make you overheat, right? It turns out that things aren't always as they seem. It is true that having longer hair on top of your head contributes significantly to the amount of heat retained. But this isn't the case with facial hair. When I had long hair and minimal to no facial hair, summers were nearly unbearable. With shorter hair and a full Beard, I'm much more comfortable even when carrying a 50 pound backpack several miles into a high mountain lake in the hottest part of the season. Why is this?
Some people think it's because the majority of heat loss is via the top of the head. Again, this conventional wisdom is incorrect. Studies show that only between 7-10% of body heat is lost through the head. So what's going on? While I don't have scientific studies with supporting data, I have a couple of ideas why facial hair doesn't significantly contribute to heat retention. First, Beards act as natural shade for the face. Without the direct sun hitting the skin, one naturally feels cooler. But then the question becomes: why isn't this the case for the hair on top of your head? The answer is that facial hair has different qualities than most hair on people's heads. In general, head hair is more dense, and the longer it becomes the more it acts like a blanket. Facial hair is usually more coarse and wavy/curly. Instead of creating a blanket effect, there is more air space between the hairs which allows for better air movement, which allows heat to escape more freely. Additionally, facial hair lies more vertically, so you don't end up with the blanket effect caused by multiple layers lying on top of one another.
The second reason is closely related to the first. As you start to sweat, the Beard traps the moisture. Given the additional air movement, this actually creates a built-in air conditioning effect. Any slight breeze, even the relative wind at walking speed, will help cool you down. I can genuinely say that I'm more comfortable hiking in the mid-day summer sun with a Beard than without one for these reasons.
All practical reasons aside, I would keep my Beard during the summer even if it meant I retained more heat. Why? Because...well, manliness knows no season. Because I'm a Beard guy. It's that simple. It's very similar to owning a Jeep. Jeeps have a terrible ride. They're noisy. They leak. They get atrocious gas mileage. They have no cargo space. They are, for almost every purpose, completely impractical. These facts don't stop me from owning a Jeep. Why? Because Jeeps are badass, and I'm a Jeep guy. It's that simple. When someone asks me if they should get a Jeep, I always tell them if they have to ask, the answer is, "Absolutely not." Likewise, if someone has to ask whether he should keep his Beard when it gets hot, my answer is the same.
So the answer to the question is, no, my Beard doesn't make me overheat in the summer. And even if it did, I would keep it anyway. For me, it's a bonus that my Beard helps keep me feeling cooler in the summer months, it's not a factor in deciding whether or not to keep it.