Where to buy merino wool thermal underwear?

To face the cold in the mountains without ending up like a snowman under three layers of clothing, merino wool thermal underwear remains a safe bet. Here's where to find it and which criteria to look at.

Why merino wool is particularly well suited

Merino wool is particularly prized for thermal underwear thanks to its fine fibres, which are softer on the skin than ordinary wool. It naturally regulates temperature, insulates even when slightly damp, and limits odours far better than most synthetic materials, making it a popular choice for skiing, winter hiking or simply very cold days in the mountains.

Where to find this type of underwear

• Specialist mountain and outdoor sports shops, which generally offer several thicknesses depending on use (skiing, winter hiking, everyday wear).
• Shops specialising in technical clothing, in ski resorts or in large towns near the mountains.
• Specialist outdoor websites, which often make it easier to compare compositions and fabric weights across several products.

Fabric weight (the weight of the fabric per square metre) is a useful indicator: the higher it is, the warmer the underwear, but also the thicker and less suitable for wearing under close-fitting clothes.

Criteria to check before buying

• The percentage of merino wool: some models blend wool with synthetic fibres for greater durability and a more affordable price — check the composition according to your priorities (pure wool comfort or enhanced durability).
• The fit: a close fit, without being compressive, optimises the thermal effect by limiting pockets of cold air between the skin and the fabric.
• A thickness suited to your use: a lightweight thickness suits everyday wear or intense sport, while a heavier thickness is better for static use in extreme cold.

Caring for your merino wool underwear

Opt for a low-temperature wash, ideally on a wool cycle, and avoid the tumble dryer, which can damage the fibres and cause the fabric to felt. Drying flat, in the open air, preserves the quality of the fabric much better over time.

When properly cared for, quality merino wool underwear can see you through several seasons of skiing or winter hiking without losing its thermal properties.