According to a popular 1940s US Army study, most of your body heat is lost through your head. Good, it’s incorrect. But you should always cover your noggin if it is cold. I have found that I feel as warm with a thin, tightly woven beanie as I do with a thick knitted beanie. the Smartwool Merino 150 beanie is my devotee. I strongly prefer merino wool for hats because it is soft, warm and breathable.
Mittens, which do not have individually separated fingers, are warmer than gloves because they have less surface area to lose heat. I won’t go too deep into handwear here as it depends so much on the environment and the activity.
For general guidance, gloves made only of fabric are less bulky, but the wind will bite them and they will get wet if you touch the snow. Soft-shell gloves block wind and water more effectively, but are more awkward to use. Thin windproof gloves are a compromise – cooler than full-length softshells, but with enough dexterity, and they prevent heat loss through convection by wind.
Environmental and ethical concerns
Almost all layers of outerwear for sale are produced with ingredients of animal or petroleum origin. This implies the responsibility of finding equipment that the least harm.
For wool, look for companies that source wool from suppliers that don’t practice mulesing, which involves cutting certain strips of skin around the buttocks of the sheep. They should be transparent about human conditions for animals and grazing in a way that is sustainable for the surrounding environment. Look for mentions of Responsible wool standard.
Likewise, make sure that any goose down product you purchase is ethically sourced. It should never be picked from a living animal or from animals raised in inhuman living conditions. Look for companies that adhere to the Global traceable down standard; it’s even better Global Advanced TDS.
Among outdoor businesses, synthetic fabrics these days are often made from recycled polyester. Nylon is more difficult to recycle than polyester, but it has also become common. You can usually find out about the retailer’s website or the item’s label if you shop at physical stores. Also try to buy bluesign materials. Bluesign is a voluntary set of chemical safety standards, and it can reduce environmental impact during manufacturing.
This does not solve the problem of removal of microplastics, But. These plastic fabrics release tiny particles into the laundry that are not captured by filters or wastewater treatment facilities before returning to waterways.
What about herbal fabrics?
Avoid cotton. It’s fine for the day hike in the city park or camping, but it’s awful for most outdoor activities. It’s 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 cool you down to the point of hypothermia. There is an old saying that is still popular: “Cotton kills”. Whether you are hiking in a hot desert or a cold forest, choose merino wool, goose down or synthetic fabric.