One of our favorite super stretchy, soft, and warm synthetic base layers for cool to cold conditions Our tester wore this on a thru-hike of Arizona’s 480-mile Mogollon Rim Trail in October and an Iceland traverse in August and raved about the Wolverino. Its durable mix of itch-free wool, and fast-drying synthetic fibers and design features gave us everything we want in a base layer. As a team we speak from experience that warmth truly comes from the inside out and warm kids will stay and play longer outside with less complaining. Merino wool is great at temperature regulation and will help keep you warm on colder days and cooler on warmer days. Merino doesn’t dry fast if it is not in a dry environment, however, it will still keep you warm and won’t make you feel clammy even when wet. The Cool Daily is also treated with a Polygiene anti-odor technology called HeiQ® Fresh Durable Odor Control, which seemed to work even after a week of continuous use. The fabric is 50% recycled, bluesign certified for environmentally-friendly dying, and sewn in a Fair Trade factory.

Merino wool comes from a special type of sheep called a Merino sheep. These sheep have very fine, soft wool fibers that contain lanolin, a natural antibacterial agent. Favorite features of Merino wool base layers are that they are warm when wet, are odor resistant, sustainable, and soft.One pivotal trend centers around the ethical treatment of animals and environmentally conscious practices in wool production. Brands increasingly opt for responsibly sourced wool, signifying a commitment to humane treatment and stringent environmental standards. My son can’t handle any wool next to his skin so we are a synthetic family. My son really likes the REI lightweight base layers. Jess, TMM Team Member Reima Base Layers

Lightweight wool layers are often labeled as 100 merino wool or 150 merino wool weight. Those numbers refer to the approximate fabric weight of the material in grams per meter (g/m)-so these layers are often the lightest piece of clothing in your outdoor wardrobe. A synthetic lightweight layer is often labeled “lightweight” because they’re usually heavier than their wool counterparts. MIDWEIGHT

FAQ's

By now, it’s common knowledge that taking your workout outside can be great for your mental and physical health. But this is Britain we’re talking about here, so chances are it’s going to be cold. Very cold. That’s where the best base layers come in. Synthetics are best for warmer temps, more aerobic activities, or if there is prolonged wetness (from environment or sweat). They’re also great for kids who have wool allergies. The Solution 150 won't be a perfect fit for everyone: the slim fit can be too tight for many body types to wear comfortably — especially if you're worried about the sleeves being too tight around the shoulders and pits. The NuYarn wool blend is a thin, stretchy fabric, but durability is a concern if worn alone and not safely underneath a top layer. Finally, we need to talk about the price: this is one of the most expensive base layers we've tested. Still, if you can swing the cost, you may never find yourself not wearing this hoody, from when the first flakes fall to when the last ski run closes. Thumb holes prevent my hands and wrists from feeling the chill without having to layer up with running gloves (Image credit: Julia Clarke) 2. Keeping cool The teens favorite base layers are cheap ones I got from the REI brand on clearance. TMM Team Member Rita