Functions of thermal underwear
Thermal underwear is used as the first next-to-skin layer in cold-weather protective systems. It should provide two functions:
- Retaining heat — in an insulated system thermal underwear acts as an additional heat-regulating layer.
- Wicking moisture away from the body during physical exertion — wet clothing loses its thermal protection because the thermal conductivity of water is significantly higher than that of air.
The first function (heat retention) is well handled by fibers with a complex structure: wool fibers with a scaly structure, hollow cotton and synthetic fibers, and fibers that have been brushed (napped).
The second function (moisture wicking) is performed by hydrophobic synthetic materials.
How to choose thermal underwear
Thermal underwear should be selected based on the type and intensity of the anticipated physical activity:
- Frequent alternation between periods of physical activity and rest outdoors — combined thermal underwear containing cotton or wool is suitable (able to absorb a small amount of evaporating moisture without losing insulating properties and without creating the feeling of wet clothing) — it helps prevent getting cold while at rest.
Recommendations: two-layer thermal underwear sets:
- Ambient temperature down to -15 °C — grey thermal underwear with a high cotton content.
- Ambient temperature down to -20 °C — COMFORT thermal underwear with the innovative Sanlight fiber and a fully cotton outer layer.
- Ambient temperature down to -25 °C — black thermal set with wool (15%) and cotton (25%).
- Low physical activity and prolonged stays outdoors in cold seasons — the optimal choice is thermal underwear with a high wool content
Recommendations: MONBLANC and LADY MONBLANC thermal underwear sets with the highest wool content (55%), as well as men's and women's COMFORT EXTRIM sets (45%).
- High-intensity physical activity with heavy sweating — thermal underwear with an additional polypropylene layer is suitable: this material wicks moisture most effectively.
Recommendations: three-layer COMFORT EXTRIM thermal underwear sets — they include a middle polypropylene layer that functions as a membrane.
- Continuous use in outdoor conditions (mountaineering, hiking, etc.) — thermal underwear with a high content of synthetic components and maximum wear resistance is suitable.
Recommendations: UKARI thermal underwear set with a brushed inner lining and a stretch effect.