Launched in 2003, Heattech has sold over 1.5 billion products globally, meeting the warmth needs of all ages and genders. Here are four lesser-known facts about Uniqlo's popular line.

Suitable for various temperatures

Heattech offers three distinct lines, each designed for different temperature ranges. However, many customers, whether purchasing in-store or online, often do not fully understand the specific functions of each type to match their needs.

According to the manufacturer, many believe Heattech is a singular product suitable only for extremely cold climates like Japan, Uniqlo's home country, where autumn and winter temperatures often drop below zero degrees Celsius. In reality, for sub-zero conditions, Heattech garments labeled "ultra warm" are ideal, providing warmth in temperatures ranging from -20 degrees Celsius to 10 degrees Celsius.

With its thin fabric, the extra warm version is suitable for staying warm during northern winters or when temperatures drop below freezing with snowfall. Photo: Uniqlo

With its thin fabric, the extra warm version is suitable for staying warm during northern winters or when temperatures drop below freezing with snowfall. Photo: Uniqlo

Additionally, the basic "jersey" type is suitable for temperatures between 5 degrees Celsius and 20 degrees Celsius, perfect for chilly early-season weather or extending through Tet Nguyen Dan (Lunar New Year). Meanwhile, the "extra warm" version offers 1.5 times more warmth than the basic type, ideal for temperatures from -5 degrees Celsius to 15 degrees Celsius.

Choosing the correct type for specific temperatures helps fashion enthusiasts stay warm and save on winter clothing expenses for their families.

Integrated exclusive technology

With 22 years of history, Heattech's heat-retaining fabric technology is the result of research collaboration between Uniqlo and Toray Industries, a leading global fiber manufacturer. Consequently, Heattech technology is exclusively found in products distributed by Uniqlo.

After more than two decades of development, the Heattech line has not only reshaped perceptions of winter clothing but also provided effective warming solutions for various weather conditions, becoming a hallmark in the Japanese apparel industry.

This fabric was perfected after more than 10,000 prototypes, manufactured using specialized production lines and machinery. In Japan, this line is also known as "Unibare", referring to individuals who wear Uniqlo's heat-retaining apparel.

Users directly experience the warming technology of the design. Photo: Uniqlo

Users directly experience the warming technology of the design. Photo: Uniqlo

Thin yet effectively warm

Many prioritize comfortable, easy-to-move-in clothing that provides sufficient warmth and can be layered without bulk.

According to a manufacturer's representative, Heattech's thinness initially raised concerns about its warming capabilities. However, it incorporates one of the latest heat-retaining fabric technologies. "The principle of absorbing body heat, combined with four types of fibers that retain air, provide warmth, absorb moisture, and create a smooth texture, ensures the garments are thin, lightweight, yet warm and soft against the skin", the Uniqlo representative stated.

For the Autumn/Winter 2025 season, the company introduced Heattech extra warm blended with cashmere for both men and women. A key feature is the integration of core heat retention technology with a 9% cashmere wool blend, enhancing lightness and softness.

Heattech extra warm blended with cashmere stands out for its smooth, soft feel against the skin. Photo: Uniqlo

Heattech extra warm blended with cashmere stands out for its smooth, soft feel against the skin. Photo: Uniqlo

Good elasticity, long-lasting

According to the Japanese manufacturer's representative, being thin does not mean the fabric is easily torn or quick to wear out. Instead, the brand positions Heattech for long-term use, emphasizing stretchy materials that fit well, maintaining their shape after numerous washes.

On fashion forums, many users report wearing their heat-retaining garments for multiple winters, remaining satisfied with Uniqlo products maintaining comfort, ease of movement, antibacterial properties, and odor control.

As the northern regions experience deep cold spells, understanding Heattech's characteristics will help families easily choose suitable and affordable apparel for everyone. Beyond warmth and thinness, Uniqlo's products also come in diverse colors and collar styles, meeting the needs of men and women across various age groups.

Dong Ve