Thermals, long johns, base layers â whatever you want to call them, thereâs nothing like a warm layer worn next to the skin to help keep the chill of winter at bay.
Whether youâre off skiing, hiking or cold weather camping, layering up is the best way to trap in heat and keep cosy in the great outdoors â and a good layering system starts next to the skin with a quality base layer top and leggings set.
Itâs definitely worth trying thermals on in person, especially if youâre on the tall or short side â they should hug your body without feeling too restrictive around the waistband, ankles, neck or sleeves. Some base layers are stretchier than others â we reckoned thermals with some stretch offered more warmth on test, as thereâs no empty space between the fabric and your skin for the cold to creep in.
Thermal tops usually have a crew neck or a high, zipped neck â the latter can double up as a neck warmer, and some tops also sport hoodies for extra warmth.
We also look for base layers that use flatlock stitching, which means sewing raw ends together so thereâs no bulky seam and avoids any rubbing against your skin.
Many base layers are made with synthetic materials such as polyester, but the best (but often the most expensive) base layers are made with 100 per cent Merino wool â Merino is very warm but still highly breathable, and is great at wicking away sweat. It also has naturally antimicrobial properties, making it perfect if youâre getting active or for when youâre heading into the backcountry without a shower in sight.
Bamboo base layers are more recent arrivals on the market â theyâre also a great choice, as theyâre soft to wear, antimicrobial and more eco-friendly to produce than synthetic materials. You may see base layers listed with a number, such as 140 or 220 â this refers to their weight in grams, and the higher the number, the warmer, but heavier, the base layer. We tested out the latest base layers on cold weather hikes and compared them for warmth, breathability and comfort.
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