Top Thermal Apparel Brands for Ultimate Warmth

As temperatures begin to drop, staying warm becomes a top priority for many, making thermals an indispensable part of wardrobe essentials. In the world of thermal wear, choosing the right brand can make a significant difference in comfort and warmth during those chilly months. Whether you're planning an outdoor adventure or simply looking to stay cozy indoors, selecting quality thermals ensures that you can tackle the cold with confidence. If you're curious to discover the top brands that excel in delivering warmth and style, take a look below.

Illustration of thermals

Best brands of thermals in 2025

Uniqlo

Uniqlo has established itself as a leading producer of thermals, particularly through its innovative HeatTech fabric, which converts moisture into heat and retains it, making the clothing both thin and comfortable. This technology has seen significant growth, with sales of HeatTech products increasing from 1.5 million units in 2003 to over 130 million units in 2012. The brand's focus on high-quality, functional materials has driven its success, with Uniqlo Japan reporting a 18.0% increase in operating profit in the first quarter of 2023, largely due to strong sales of winter thermal ranges like HeatTech innerwear and fleece. Uniqlo's strategic approach to product development and efficient supply chain management has enabled it to maintain competitive pricing while ensuring high product quality. The brand's commitment to innovation and customer-centric culture has contributed to its global recognition and growth.

Patagonia

Pioneering in environmental protection and sustainability, Patagonia is renowned as one of the best producers of thermal underwear. Founded by Yvon Chouinard in 1973, Patagonia has led the industry in using renewable energy and organic materials, highlighted by their switch to 100% organically grown cotton in 1994. Their commitment to durability and waste reduction is central to their mission of protecting the environment, a sentiment echoed in their 2018 mission statement, "We're in business to save our home planet." Although their high sustainability standards can be costly, allowing them to charge a premium, this strategy has fostered Patagonia's sustainable growth and reinforced strong customer loyalty.

Icebreaker

Icebreaker is renowned as one of the leading producers of high-quality thermals, particularly known for its natural performance apparel. In 2021, the brand achieved a significant milestone with 91% of its total fiber composition being merino or plant-based, and it forecasted selling over 1.3 million units of 100% merino or plant-based apparel that year. Icebreaker's commitment to sustainability is evident through its regenerative agriculture initiatives, aiming to have 100% of its contracted growers join the program by 2023. The brand is sold through over 2,500 wholesale customers and 45 retail stores across 45 countries, with a strong presence in Europe, North America, New Zealand, and Australia. Icebreaker's products include base layers and mid-outer layer solutions for men, women, and children.

Smartwool

Smartwool is a renowned brand in the thermal underwear market, known for its high-quality, comfortable, and warm products. The brand's Classic Thermal Merino Base Layer, made from 100% merino wool, is particularly praised for its stretchiness and warmth. Merino wool, which held a 42.2% revenue share in the thermals and baselayers market in 2022, is a key material in Smartwool's products. Smartwool's offerings are part of a market expected to grow significantly, with the global thermals and baselayers market projected to reach USD 32,140.9 million by 2030, growing at a CAGR of 7.3% from 2022 to 2030. Explore their new arrivals to discover the latest innovations in warmth and comfort.

Under Armour

Under Armour is a leading innovator in the athletic apparel industry, known for its high-quality thermal underwear that caters to consumers with active lifestyles. The brand, which was founded in 1996, initially focused on compression shirts for men but has since expanded to include a wide range of performance products for both men and women. In the financial year ended March 31, 2024, apparel sales, including thermal underwear, accounted for approximately 66.5% of Under Armour's worldwide revenue, highlighting the brand's strong presence in the market. Under Armour's commitment to innovation and responding to consumer preferences has driven significant growth, with global net sales exceeding $5 billion for the first time in 2018. The brand's thermal underwear is designed to provide insulation and retain body heat, making it a popular choice among outdoor enthusiasts and everyday consumers.

Columbia

Columbia Sportswear's Columbia brand is renowned for its high-quality thermal products, particularly with its innovative Omni-Heat Infinity technology, which has garnered praise for its lightweight performance and was included in several 'best of' lists. Despite a warm winter, Omni-Heat Infinity showed strong growth in 2023, contributing to the brand's full-year sales of $2.95 billion, a 3% increase in constant currency compared to 2022. The brand's focus on innovation, performance, and style is aimed at attracting younger consumers and enhancing its market presence. Columbia's market share in the apparel and footwear sector stands at around 2.27% as of Q3 2024. The company's commitment to innovation and brand experiences is key to its growth strategy.

Base Layer

The base layer market, led by brands like Kari Traa and others, is witnessing significant growth driven by technological advancements and changing consumer preferences. For instance, the global base layer market was valued at USD 8.78 billion in 2023 and is anticipated to grow with a CAGR of 4.6% through 2029, with online channels being the fastest growing segment. Brands like Kari Traa offer a range of base layers and thermals crafted from materials such as 100% merino wool, known for their excellent insulation and natural antibacterial properties. These products cater to the evolving needs of fitness enthusiasts, athletes, and outdoor enthusiasts, with a focus on sustainability and smart technologies. The market's shift towards high-performance and eco-friendly base layers is a key driver of its growth.

Helly Hansen

Helly Hansen is renowned as one of the best producers of thermal clothing, with a legacy spanning over 140 years. The brand pioneered the first technical base layer, LIFA(r), in 1970, which remains a cornerstone of their three-layer system consisting of LIFA(r) (base layer), Pile or LIFALOFT(r) (midlayer), and HELLY TECH(r) (outer layer). This innovation has enabled Helly Hansen to cater to extreme sports such as sailing and skiing, with their gear used by over 55,000 mountain professionals and guides in more than 200 ski resorts. The company has seen significant growth, with sales rising by 7.1% in 2023 to C$837.2 million, and they have expanded their digital presence with 55 different sites in seven languages, boosting their mobile traffic by 48% and overall revenue by over 45% since their e-commerce platform launch in 2016. Learn more about their innovative gear on the official Helly Hansen website.

The North Face

The North Face is a leading brand in the outdoor retail industry, renowned for its high-quality thermals and innovative outdoor wear. With 165,000 monthly brand searches, it has established itself as a prominent name in both sportswear and fashion. The brand's Thermoball synthetic insulation, which mimics the capability of down, is a game-changing product line. In 2024, The North Face reported a 17% increase in revenue to $3.6 billion, with significant growth in the Asia-Pacific region, driven by a 35% increase despite unfavorable currency exchange rates. The brand's products are marketed globally through various channels, including specialty outdoor stores and online platforms.

L.L.Bean

L.L.Bean is a prominent player in the thermal underwear market, known for its high-quality and durable products. The brand is part of a market that was valued at USD 7,951.13 million in 2022 and is expected to grow to USD 11,036.07 million by 2031, with a CAGR of 3.71%. L.L.Bean's products contribute to the dominant market share held by North America, which accounted for 43.60% of the global thermal underwear market in 2022. The brand's commitment to quality and customer satisfaction has helped it maintain a strong presence in the industry. As the market continues to grow, driven by factors such as an increasing number of women in the workforce and demographic changes in emerging economies, L.L.Bean remains a trusted name for thermal underwear.