There is an art to keeping yourself warm in various weather conditions, from wet and windy to cold and snowy. The way you dress, whether you’re inside your house or going on an outing, is key to maintaining a comfortable body temperature.
We lose heat through evaporation (sweating), radiation (heat moves away from the body), conduction (such as sitting on the cold ground) and convection (having the wind blow on you). The body loses 65 percent of its heat through radiation, so preventing heat from escaping is the simplest way to stay warm.
John Fischer, 65, knows a thing or two about dressing for the weather. He forecasted the weather for KEZI for 25 years, while also volunteering for a number of years on a ski patrol and search and rescue. “You also need to know how to dress based on what you’re doing,” he says. “If you’re doing something active and you get sweaty and your clothes get wet, you’re going to get cold.”
For instance, if you’re digging a hole or shoveling snow off the driveway, your body heats up from the activity. Then you get sweaty, and your clothing may trap the sweat, which can start to wick away your body heat, making you colder even though you’re being physically active. It’s natural to want to take off your coat, but put it back on as soon as your activity is finished.
Wear a base layer that wicks moisture away from your skin and moves it to an outer layer, Fischer says. The second layer should be breathable so that the moisture escapes rather than builds up. Fleece is a good choice for a breathable layer because air can permeate it easily.
The materials you choose to wear when you’re outdoors makes a huge difference in comfort and safety. “Blue jeans when they get wet are horribly cold,” he says. “Wool and polar fleece on the other hand, stay warm when they’re wet. But most importantly, of course, you don’t want to get wet.”
Fleece is a synthetic fabric meant to mimic wool. In general, wool retains heat well even when wet, and is more water-repellent. Fleece absorbs water more readily than wool does, but also dries out faster.
Wearing wool in your coat, hat and scarf will protect you from rain and wind better than anything cotton or polar fleece. If you’re just walking to the grocery store, though, go ahead and wear that cotton shirt or polar fleece hat, as you’re not trying to dress for a survival situation in that case.
Fischer says many of us get confused by wind chill, which means the body loses heat faster when the wind is blowing. “To a rock that’s placed outside in 30-degree weather or when the wind is blowing 100 miles an hour, it’s always 30 degrees,” he says. “But a human will lose heat as the wind increases, so you’ll feel like it’s colder.”
Layering is important because if you’re intermittently active you need something easy to take on or off.
Wear something thin and comfortable next to the skin. Ideally this will be a thin, soft layer that helps hold heat in. “Most people wear pants and then a giant down jacket to try to stay warm, but they don’t wear long underwear under their pants,” Fischer says. “You can only wear so many jackets so then you have nothing more to put on or take off.”
Jeff Fan of Backcountry Gear outdoor gear store in Eugene says there are usually different weights of fabrics for layering, such as lightweight, midweight and heavyweight. “And then every single company has their own version of that,” he says. “So, I believe a smart rule is to use a lightweight or microlayer for the base layer and have three or four different layers of thicknesses.”
Fan likes to have a base layer, followed by fleece and another layer of insulation, like a jacket. The type of outer layer you choose depends a lot on the environment you’re in or the environment you’re going into.
For instance, a Gore-Tex outer layer is great protection against rain and wind. A down jacket offers superior warmth, but down is not ideal to wear in rain. “A Gore-Tex tends to be a little bit more expensive initially, but it’s much easier to take care of and it works much better than your more generic, lower price point jackets,” he says.
Down has always been the go-to outer layer for warmth, and a lot of modern down jackets have fabric treatments that help them stay drier in the rain. But in a downpour, even these treated jackets will get wet and lose their thermal properties. Your outer layer should fit easily over your other layers, without being so loose that all your warmth escapes. And it should still allow you to move freely.
It’s harder to stay warm as we age because our metabolism slows and we often lose subcutaneous (under the skin) fat. Both contribute to bodies not generating enough heat to feel warm. Other medical conditions such as anemia, diabetes and hypothyroidism can contribute to a feeling of coldness.
While Fischer has been able to grow a long, thick beard since he left television, he’s not got as much hair on the top of his head as he used to. For older folks with hair loss or thin hair, wearing a hat is especially important.
There’s a common saying that people lose most of their body heat through the top of their head. Fischer says this isn’t true. “What it means when people say you lose 50 percent of your body heat through your head is that the rest of your body is covered up and your head is the only part that’s not protected,” he says.
In reality, we lose about 7 to 10 percent of body heat through our heads, no different than any other part of the body that remains uncovered.
Don’t forget about wearing good shoes. In western Oregon, we deal mostly with wet weather, so avoid water-absorbent shoes. “Don’t wear tennis shoes,” Fischer says.
Rubber boots with comfortable wool socks help keep our feet warm. Look for ones with good grips on the bottom. “Sometimes when you’re walking along a trail or even a sidewalk, when there’s leaves on the ground and it’s raining, the leaves can be pretty slippery,” Fischer says. “Leather-bottom and flat-bottom shoes are more inclined to slip.”