Bundling Up: A Brief Guide to Thermal Clothing

Whether you’re an outdoor adventurer, or you just suffer a short commute to work in the morning, you’ll have the same goal as you step out the door during winter: stay as warm as possible. Layering your clothes to create an effective fortification against the biting cold allows you to enjoy the winter months much more, and, according to this Harvard Medical School article, can help you stave off respiratory diseases and spikes in blood pressure too.

To combat the cold, clothing manufacturers started making what’s known as “thermal wear” – clothing specifically designed to retain heat. But all thermal wear isn’t created equal, and the term is used by some brands to simply refer to a line of clothing is warmer than others (though not especially heat retaining).

This article will look at the standard way of quantifying the thermal property of clothing, as well as what to look for when you buy thermal wear.

The TOG Rating

The TOG rating – or, Thermal Overall Grade – is a scientific test determining the heat retaining capacity of various articles of clothing and bedding. You’ll often see duvet makers flaunt their TOG rating, but arguably (at least for those with indoor heating) the TOG rating means more when applied to clothing.

The average thermal sock is about 0.89 TOGs. You can compare that to your average cotton sock, which is about 0.33 TOG. But if you really want a heavy hitter, you have to go with a brand like Heat Holders, whose socks boast a very impressive 2.34 TOGs.

What Makes Clothing “Thermal”?

Let’s stick with Heat Holders as the example, since they make the highest TOG rated thermal wear on the market. According to their website, their high quality thermal socks for men and women are made using high insulating yarn that’s knitted in such a ways as to create an extra long looped pile (in layman’s terms, a looped pile is essentially the raised structure of cloth).

That tells you that there are two important factors to look for in thermal clothing: the yarn used, and the ways in which that yarn is structured. Both have a profound impact of the heat retaining capacity of the final product.

What to Look For in Thermal Wear

Find thermal wear that advertises their TOG rating so you know what to expect. Again, a great place to start your search is with Heat Holders. If it is sheer heat retaining capacity you are after, they are your first choice. Conversely, be wary of brands that advertise a thermal line, but make no mention of what exactly makes the clothing “thermal”. And be wary of ad copy that withholds the TOG rating.

Staying warm in the winter isn’t about staying cooped up inside; it’s about making informed clothing choices and bundling up properly. Before you reach for a regular pair of cotton socks or underwear this winter, consider thermal wear, paying close attention to the materials and the TOG rating. That way, when it’s time to greet the day, you can do so with a warm welcome.