There’s a popular US Army study from the 1940s that says you lose most of your body heat through your head. Well, it’s incorrect. But you still need to cover up your noggin if it’s cold. I’ve found that I feel just as warm with a thin, tight-weave beanie as I do with a thickly knitted one. The Smartwool Merino 150 Beanie is my stalwart. I strongly prefer merino wool for hats because it’s soft, warm, and breathable.
Mittens, which don’t have individually separated fingers, are warmer than gloves because they have less surface area by which to lose heat. I won’t go too deeply into handwear here as it depends so much on the environment and activity.
For general advice, gloves made only out of fabric are less cumbersome, but the wind will bite through them, and they’ll get wet if you touch snow. Soft-shell gloves block wind and water more effectively but are clumsier to use. Thin wind-blocker gloves are a compromise—less warm than full-on soft shells, but dextrous enough, and they prevent convective heat loss from wind.
Environmental and Ethical Concerns
Almost every layer of outdoor clothing for sale is the product of either animal- or petroleum-based ingredients. That brings with it a responsibility to seek out gear that does the least harm.
For wool, look for companies that source wool from suppliers who don’t practice mulesing, which is the cutting away of certain strips of skin around the sheep’s buttocks. They should be transparent about humane conditions for animals and grazing in ways that are sustainable for the surrounding environment. Look for mentions of the Responsible Wool Standard.
Likewise, make sure any goose-down product you buy is sourced ethically. It should never be plucked from an animal live or from animals kept in inhumane living conditions. Look for companies that adhere to the Global Traceable Down Standard; even better is Advanced Global TDS.
Among outdoors companies, synthetic fabrics these days are frequently made from recycled polyester. Nylon is harder to recycle than polyester, but it’s become common too. You can usually find out on the retailer’s website or the item’s label if you’re shopping in physical stores. Also, try to buy bluesign materials. Bluesign is a voluntary set of chemical safety standards, and it may reduce environmental impact during manufacturing.
That doesn’t alleviate the problem of microplastics shedding, though. These plastic fabrics release tiny particles in the laundry that aren’t captured by filters or wastewater facilities before they wash back into waterways.
What About Plant-Based Fabrics?
Avoid cotton. It’s fine for day-hiking in the city park or camping, but it’s horrible for most outdoor activities. It gets wet and takes forever to dry, and unlike wool it doesn’t keep you warm when wet. Even if it’s not what you consider very cold outside, being wet for long periods of time can chill you to the point of hypothermia. There’s an old saying that’s still popular: “Cotton kills.” Whether you’re hiking in a warm desert or a cold forest, choose merino wool, goose down, or synthetic fabric.