Letters
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?
I feel like I go to school each day with MDK! Thanks for all the teaching and encouragement. Who knew wool was so multifaceted. True multitasker
The core of my summer wardrobe has become my sleeveless wool dresses from Woolx. And I live in Florida!
Not brave enough to to knit one….
I was just looking at those dresses! I live in Georgia and travel was my primary focus but looks like I’ll be able to make much more use of them!
I have a large stash of cotton and linen for all of the purposed benefits but think I’ll go ahead and cast on that wool tshirt now!
I went 100% wool last summer (with the exception of a handful of linen items) and have never looked back. When I tell people I’m wearing wool in 90 degrees plus they look at me as if I’m insane. Instead I’m cool and comfortable. I will never go back.
Fun and so interesting
Thank you
I am really looking forward to hearing about your experience with the wool swimsuit!
Also think of the clothing of African or Arabian desert peoples.
Perhaps, altho anything other than cotton or linen in NYC heat would kill me!
Also, I think perpetuating the cotton kills is a disservice as it certainly doesn’t kill more than synthetics, and, like most other synthetic fibers, it only kills in very specific and extreme circumstances.
Great article. I learned so much. Several years ago, I walked the Susan Komen 3-day 60-mile Walk for the Cure. I did it four years. And one of the first things we learned in the training is no cotton socks. They led to blisters, because they were always wet. I love cotton and linen, and have only recently begun to explore the world of wool for summer. As always, great writing and education. Thank you.
I hike a lot year-round and use wool for 3 seasons, as the odor-eliminating properties are real (stinky when I take off my shirt, but not stinky the next day when I put it on again). Unfortunately, I can’t wear wool in the summer heat outside hiking – it is just that extra bit too warm compared to microfiber, and I get overheated. The exception is my wool Darn Tough socks which I wear year-round. The expression “cotton kills” comes from sweating in cotton, then when you stop moving, or the temperature drops, you can become chilled very quickly from the wet cotton. Wet wool will still keep you warm. My 2 cents.
I do have a question about that indelicate subject…do you really wear exercise clothes or socks a few times between washing? Intellectually I understand these benefits but emotionally I’m having a harder time wrapping my head around it.
Yes!
A friend convinced me to try some wool t-shirts for travel a couple of years ago. Not only do they hold up well to multiple wearings, they look just a little bit nicer than cotton t-shirts so work a bit better for dressing up, as well as down.
I’m having a hard time getting my head around a wool swimsuit though — please report.
Thank you! We cruise often and it’s hard to keep that bag under 50 pounds so having flexible separates is essential. I’ll order some!
Also very interested in the reports about the wool swim suit…something that also takes up too much space in the suitcase…I wish there were more options without giant fake boobs! 🙂 especially for travel.
Yes you have! I have been pondering this since Spring. My question is, the weight and gauge must factor in as well, no? Fingering wt at a looser gauge without defeating the sunscreen benefits? Thanks!
I live in a hot-in-summer and cold-in-winter climate and have been wearing merino clothing year-round. There are a ton of sources for merino clothing, all of it seems to be really well made so it is just a matter of personal preference. I would suggest checking return policies so that you can try on and find the proper style and fit. I like a bit of drape not a tight fit and have returned many form-hugging t-shirts.
Some of my finds? Woolx 3/4 sleeve tees fit me well, not too baggy and not too tight. MerinoTech tees one size up for the gym. On a hot summer day Icebreaker culottes are incredibly comfortable, as are Unbound Merino Travel Pants. Woolx has nice winter pants, and year-round merino pajamas. I like the merino underwear from Wooly.