Life With Wool: Perpetual Sunscreen and AC

Greetings from Maine!

I realize that the mere mention of wool right now might feel like I’m offering you another helping of turkey and stuffing at the end of Thanksgiving dinner. It’s July. Summer is at its height. Heatwaves abound. Who on earth wants to talk about wool?

Contrary to what many think, wool is an excellent companion during the summer months. Yes, those hefty sweaters are too much. That’s why they’re sound asleep in the closet.

Thanks to the miracle of modern spinning, weaving, and knitting technology, we get to enjoy far finer permutations of wool in T-shirts and tunics and tank tops and dresses and leggings and shorts and night shirts and socks and even bras and underwear. I’m a firm believer in all these incarnations, and I’m eagerly awaiting the arrival of a new wool swimsuit to complete my summer wool wardrobe…for now.

We have many reasons to love wool during the summer.

First and foremost, there’s insulation. We know what a good insulator wool is in the winter. But the insulation door swings both ways. It keeps warm things warm, and it keeps cold things cold. Think of that cooler you bring to the beach. Wool fibers act as barrier and buffer zone between your body and whatever the weather throws at you. In this era of extreme temperature swings and overzealous air conditioning, having an effective buffer zone is no joke.

But what are the fibers actually doing? This brings us to an indelicate but necessary subject of sweat. Our bodies are built to release moisture in hot weather in order to help us thermoregulate. Call it perspiration, call it dew, call it the gentle glistening of a life well lived.

This seems impossible to believe, but when we exert ourselves in extreme heat, our bodies are capable of releasing upwards of 3 liters of moisture per hour. That’s twelve cups of water. Per hour. Not only do we need to stay hydrated, but we also need to clothe ourselves in fibers that know what to do with all that moisture.

The normal prescription for hot weather is to wear plant fibers like cotton or linen. They’re superb at absorbing moisture. As they do so, the fibers spread the water molecules out along their surface so that they can evaporate—cooling our bodies in the process.

Excellent! That’s everything we need during a hot summer, right?

Historically, yes.

But today, we frequently find ourselves moving between two extremes: the great outdoors and the greatly air-conditioned indoors. Linen and cotton have only one setting: cool. Their internal AC won’t shut off if it detects colder air, leading to your body feeling even colder. The phrase “cotton kills” sounds dramatic, but there’s science behind the advice not to wear cotton on hiking expeditions that might involve sudden temperature changes.

Wool is similarly absorptive, but it moves moisture molecules further away from your body before storing them or releasing them into the environment. The evaporation happens on the outside, while the fibers trap still air, buffering your tender skin from the cold or any other slings and arrows the world’s HVAC systems may throw at you.

By keeping our dewy skin reasonably dry, wool creates an environment that’s hostile to the build-up of odor-causing bacteria. Which is to say, wool doesn’t just soak up sweat; it also keeps you smelling as fresh as a daisy.

There’s another superpower that wool brings to the table. Without any chemicals or sprays or treatments whatsoever, wool fibers absorb radiation across the entire ultraviolet spectrum, including the sun’s UVA and UVB rays. Wool is a perpetual sunscreen.

Depending on the color and thickness of the fabric, wool can provide a UPF, or ultraviolet protection factor, of 30 or higher. That cotton T-shirt or linen tunic, on the other hand, barely squeaks out a UPF of 5.

So not only does wool act as a dry towel and powerful deodorant, but it also provides built-in sunscreen. On more than one occasion, I’ve draped an airy wool scarf over my exposed skin when I can feel it getting hot. It’s not the same as a thick slather of sunscreen, but it’s something.

A whole industry of UF-protective clothing has sprouted up in recent years. You can find hats and shirts and swimsuits and Bermuda shorts and coverups and all sorts of outdoorsy summer things that have been specially treated to provide a UPF of 50 or higher.

But when you check the fiber content, you’ll notice that the vast majority of this clothing is made of petroleum-derived synthetic fibers—the same synthetic fibers that offer zero relief for those 12 cups of water you’re sweating while you play shuffleboard on the lido deck.

This high UPF rating is often obtained through special chemical treatments that will, over time, degrade with exposure, washing, and regular wear. Invest in a wool top and you might miss a few points of UPF protection, but what it does offer will never, ever go away.

So, you have insulation, a clean towel, deodorant, and sunscreen—none of which will ever let you down. Have I convinced you to try another plate of turkey?