People usually wear these pants to feel warm in cold weather, however, they are great for lounging around at home, too. Thermal underwear can take the bite out an icy blast of wind. The material also makes it easy to dress in numerous clothes underneath since these pants are tight fitting and will fit easily fit underneath a pair of regular pants. Often they rise a bit higher than the waistline, so they also help from getting exposed to the cold air which can reduce the risk of frostbite and other illness.

There are other styles of these pants and other reasons to wear them, too. For instance, compression thermal pants can boost blood circulation to your leg muscles which increases oxygen flow. More oxygen flow will lead to less lactic acid which helps prevent cramping or other potential injuries to your muscles. Compression thermal pants are perfect for outdoor athletes, such as soccer players, football players, rugby, lacrosse, track runners and more. Wicking features can help your body remove sweat faster which helps prevent skin rashes or chaffing. This also helps reduce body odor.

These are just a few reasons people turn to thermal pants. The most common application is to help you stay warm in cold weather. However, these pants are useful in the gym or on the track or field also. They can help reduce injury from fatigued muscles and from the harshness of the cold.

The way a pair of thermal pants fits serves several functions. The most important of these is heat retention. For a piece of clothing that needs to trap heat next to the skin in order to provide warmth, failure to fit snug against the body eliminates this function altogether.

Another element greatly affected by the fit is comfort. This is an obvious one, especially if you’ve ever worn a pair of traditional long johns. These cotton monstrosities didn’t’ fit in any way to speak of. They were suspended by an elastic waistband that was usually way too tight, and they just kind of hung there, being constricting more than anything else. Thankfully, artificial fabrics have gained in popularity, and these conform to your shape, giving a much more comfortable fit.

Even with the use of these wonder fabrics, the fit is still an issue. Now, these pants have to fit as accurately as possible, because spandex, polyester, and other like materials are not forgiving at all, and the wrong fit can be just as uncomfortable and cumbersome as the older style ever was.

Obviously, having a proper fit comes down to a combination of the right choice of fabric, and the manufacturer taking care to ensure their sizing fits as true as they can make it.

There are two main styles when it comes to thermal pants. Either they are meant to be hidden away as a base underneath to a complete set of winter gear, or they are proudly displayed by athletes as compression wear. Whatever the function, thermal pants are meant to keep you warm no matter what.

Very popular with hunters and other outdoor enthusiasts, thermal underwear, or long johns, is the perfect starting point for any winter wardrobe. Long johns are best known for being made from cotton and having a waffle weave pattern on them. This style is also known for its high level of warmth. Unfortunately, they aren’t very comfortable, as cotton doesn’t have a lot of structure, so there is nothing outside if a waistband to keep them tight to the body. Another sore spot for the older style of long johns is that once they get wet, they tend to stay that way for a long time. These negative attributes made long johns more of a reluctant necessity than anything else.

For athletes, keeping warm is a bit different. Because of the requirements of their sports, they usually are unable to wear any clothing underneath, since doing so could make movement awkward and could also result in overheating. For them, thermal pants need to be the only layer they wear, keeping body heat trapped inside where it belongs, while keeping moisture out. To make this work, the same materials found in modern long johns are utilized here. These fabrics, typically comprised of either polyester or some other similar synthetic fiber, have all the properties athletes need. They are very breathable and they stretch, allowing for full movement. On top of that, many of them also act as compression pants, giving increased support for those long workouts.

Because both types of thermal pants are so alike in their properties and construction, they can, for the most part, be used interchangeably.

Thanks to innovations in fabric, however, long johns have come screaming back into popularity. New materials have allowed them to be completely form fitting, greatly improving comfort and flexibility. Also, these new materials are inherently breathable, which not only helps prevent sweating, they also take any moisture away from the body, ensuring long-lasting warmth.

The primary reason people use thermal pants is to stay warm. These pants form thermal barriers around your legs which lock in your body heat and keeps cold air out. Some of the more premium thermal pants will feature wool and cotton to help you stay extra warm in more extreme cold weather. Such features make thermal pants ideal for working outdoors or spending time on the ski slope.

There are other reasons why people wear thermal pants. Many athletes benefit from thermal pants because they help wick away moisture and perspiration. This helps keep your skin dry and helps reduce issues such as rashes or chaffing. The more premium brands of thermal pants offer a compression fit that helps promote blood flow to your leg muscles. Having more blood flow promotes oxygen flow and reduces lactic acid, which can help prevent injuries.

Of course, it’s important that the thermal pants are comfortable. Pants that do not feel right or are itchy do not have a lot of value. It’s important to read the size chart and make sure that the thermal pants you are purchasing are the correct size. Since these pants tend to fit very tight, there isn’t much room for error.

For the most part, thermal pants are not going to cost all that much, and there also won’t be a significant difference in price points. Obviously, pants made with an athletic purpose in mind can cost more than just plain long johns, but even this doesn’t make much of a difference price wise.

Where the exception lies is with the brand name, and this is pretty much reserved for the athletic side of thermal pants. As basic pants, all brands are going to achieve the same results. They are going to keep you warm and dry, and they are going stretch when you need them to. In some cases, they are going to act as compression pants as well, but this feature doesn’t really call for any increased cost, as the materials used are often the same as for thermal pants. No, when you put on a pair of thermal athletic pants that cost you hundreds of dollars and trust me, they exist, you paid for one unique feature: the brand.

Don’t get me wrong, the popular brands got that way because they make good products, for the most part. The problem here is that these companies know that people will pay more for their name, so they gamble with their perceived quality, often times diminishing it in the name of cost saving.

Maybe you’re the type of person who reads a value in specific brands, and that is absolutely fine. Just keep in mind though, that you are just as likely to get optimal results in a $20.00 pair as you are from any other pair. In the end, this is solely a matter of personal preference.