What Are Long John Shirts Called in USA?

These materials, often a blend of polyester and cotton or wool, trap body heat and provide an extra layer of protection against the harsh elements. In the United States, long john shirts, or thermal shirts, have become a staple in winter wardrobes, especially in colder regions where temperatures can plummet to freezing levels. With their form-fitting design and moisture-wicking properties, they not only keep you warm but also help regulate your body temperature and keep sweat at bay. So, when the frosty season arrives, don't forget to stock up on these versatile undergarments commonly referred to as long john shirts in the USA.

What’s a Canadian Long John?

When it comes to winter clothing in Canada, one essential item that many people rely on is the Canadian Long John. These thermal long underwear are commonly worn during the harsh winter months to provide extra warmth and insulation. However, in regions such as Vancouver, where the weather can be milder compared to other parts of Canada, the decision to don these fashion pieces can be tricky.

Made from soft, breathable materials such as cotton or wool, these long johns are designed to trap body heat and keep you warm in chilly conditions. They typically come in a variety of styles, from form-fitting to loose-fitting, to suit individual preferences.

In Vancouver, the weather can be unpredictable, with milder temperatures and occasional rain showers. This often leads to the dilemma of whether to wear long johns or not. While the usually milder climate may not require the constant use of long johns, they can still be beneficial during colder spells or when engaging in outdoor activities.

Long johns, in American slang, refer to long underwear or thermal undergarments. These garments are worn to provide warmth during cold weather conditions.

What Does Long John Mean in Slang?

In American slang, the term “long john” has a slightly different meaning than it’s traditional usage. When referring to long johns in American English, it takes on a more informal connotation. In this context, long johns are synonymous with long underwear, which is worn to provide extra warmth during colder weather conditions. These undergarments typically cover the entire legs and sometimes include a matching top.

They’re designed to trap body heat and provide insulation against the cold. Many people wear them under their regular clothing, especially when participating in winter sports such as skiing or snowboarding.

They’re often made of materials such as cotton or wool, which are known for their warmth-retaining properties. The snug fit of these garments ensures that body heat isn’t easily lost, keeping the wearer comfortable in cold temperatures.

While long johns are primarily functional, they’ve also found their way into fashion and popular culture. Some people even wear them as loungewear or pajamas, appreciating their cozy and comfortable feel. Additionally, long johns have been featured in movies and TV shows, often depicted as a humorous or endearing element of a characters attire.

They’re common in places with lower temperatures and are designed to trap body heat and provide insulation.

Long johns, the popular thermal underwear, have a fascinating history rooted in Derbyshire, England. John Smedley’s Lea Mills, established over two centuries ago, played a pivotal role in their manufacturing. Surprisingly, these cozy garments are believed to be named after the renowned late-19th-century boxer, John L. Sullivan. In a remarkable continuation of tradition, John Smedley’s Lea Mills continues to produce long johns today.

Why Are Long Johns So Called?

The origins of the name “long johns” can be traced back to the renowned John Smedleys Lea Mills in Derbyshire, England. This historic company, with a remarkable 225-year heritage, played a significant role in the creation of these iconic garments. It’s said that long johns were named after the famous late-19th-century heavyweight boxer, John L. Sullivan.

Their expertise and dedication have been instrumental in keeping this timeless garment alive and well. Despite the passage of time, the company continues to manufacture and supply long johns to this day.

Long johns, also known as thermal underwear, play a crucial role in providing warmth and comfort during colder months. They’re typically worn as a base layer beneath clothing, providing an extra layer of insulation against the cold.

The Different Types of Long Johns Available and Their Features

  • Classic long johns: Made of comfortable fabric, these long johns are suitable for everyday wear. They provide insulation and moisture-wicking properties.
  • Thermal long johns: Designed for extreme cold, these long johns have extra insulation and a snug fit. They keep you warm and prevent heat loss.
  • Merino wool long johns: Known for their natural warmth and breathability, these long johns are perfect for outdoor activities. They’re odor-resistant and regulate body temperature.
  • Fleece-lined long johns: With a soft fleece lining, these long johns offer exceptional warmth and coziness. They’re great for cold weather and can be worn as base layers.
  • Silk long johns: Lightweight and luxurious, silk long johns provide excellent insulation while feeling silky smooth against the skin. They’re ideal for layering under clothes.
  • Compression long johns: These long johns offer compression for improved circulation and muscle support. They’re commonly used by athletes and for recovery purposes.
  • Heated long johns: Equipped with heating elements, these long johns provide extra warmth in extremely cold conditions. They often come with rechargeable batteries.
  • Moisture-wicking long johns: Designed to keep you dry, these long johns wick away sweat and moisture from the skin. They’re perfect for active individuals and sports.
  • Anti-odor long johns: Made with special fabrics, these long johns prevent the buildup of odor-causing bacteria. They’re suitable for prolonged wear and travel.
  • Windproof long johns: These long johns have a windproof outer layer to protect against cold winds. They’re ideal for activities in windy and chilly conditions.

Source: Long underwear – Wikipedia


These versatile garments incorporate thermal, insulating materials designed to trap body heat and keep it close to the skin. Whether you're engaging in outdoor activities or simply seeking comfort during chilly days, thermal shirts are a reliable option to ensure warmth without compromising style or mobility. So, next time you encounter the need for an extra layer of snugness during the winter months, don't hesitate to reach for a thermal shirt and experience the comfort it provides.

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