The Six Best Thermal Top Reviews

For those of us working as security guards or door supervisors a typical shift at work is anything but typical. One day you might find yourself standing outside in a snowstorm in a Hi Viz Jacket with very little physical activity; the next you could spend hours lifting supplies or walking. You might be outside in freezing winds and a few months later in the scorching suns of summer. In order to be comfortable in these variable climates and work activities, proper work gear is vital. 

One of the most important pieces of gear for those of us in this industry is a quality mens base layer. You might wear this layer alone on warmer days or during strenuous activity, or layer it under heavier materials on a cold or sedentary day. Either way, it’s best to be well-informed so you can make the right choice for optimal comfort. 

In this article, I’ll give you a quick rundown of the basics of layering, the requirements for a proper thermal base layer, and follow it up with a review of a few different thermal base layers to make the decision as easy as possible. 

Why do you Need a Base Layer?

Keeping warm whilst working in outdoor activities can seem complicated but knowing the different layers and their purposes will help you choose the right gear for your specific needs. Depending on your climate and level of activity, you could use a base layer alone, a base layer and a midweight layer, or if it’s really cold and you’ll be standing still a base layer, midweight layer AND a heavyweight outer layer might be needed. 

What’s most important is that the thermal base layer keeps you warm and comfortable. Here’s how it works. 

Cooling and heating of the body can happen through four different processes. 

  • Conduction is the contact between two different surfaces of different temperatures. Your warm body coming into contact with cold air is an example. 
  • Convection energy loss happens when wind pulls the heat away from your body. 
  • Radiation heat loss occurs when there is a transfer of heat without direct contact via infrared rays; think sun heat. 
  • Evaporation is the energy loss that occurs when a liquid turns to gas. Evaporation occurs when we sweat. 
how wiking works

Conduction, convection and radiation heat loss are all best dealt with through the wearing of layers. The more layers you wear, the more heat is trapped between them. This is why we bundle up on an extra cold or windy day; you feel markedly less cold if you’re wearing a few extra layers.

Depending on your climate and circumstances, you might want one or two layers (or even three if you want to throw on a rain shell too) but no matter what, you’ll want a good base layer. Base layers are the primary method of dealing with the last source of heat loss, evaporation, All mammals sweat. 

This is the body’s way of monitoring body temperature and making sure we don’t overheat. Overheating might sound like just being uncomfortably hot, but true overheating can lead to organ failure and even death. Sweating cools the body naturally, and for humans helps to keep us at a natural body temperature of 98°F. 

This natural evaporation of liquid is a negative when you are trying to stay warm while performing vigorous, sweat-inducing activity. The evaporation of liquid cools the surface is evaporating away from. Additionally, if the sweat can’t move away from your skin it will cool rapidly and keep you cold even under heavier layers. 

For this reason, base layers are designed to act as a kind of ‘second skin’. The base layer should be able to able wick sweat away from your skin by absorption, but also dry quickly to keep you from getting chilled by conductive contact between your skin and the wet material. 

For cold or moderate temperatures, a base layer should keep you dry by moving moisture away from your skin. In hotter temperatures, the goal of a base layer is to assist in the body’s natural evaporation process to keep you cool. Base layers need to be incredibly tight in order to accomplish these goals. 

How to Wear a Compression Shirt

Choosing the right base layer

Base layers come in a wide variety of fabrics, and each one has its own specific pros and cons. 

Cotton base layers are the most commonly available base layers, including things like t-shirts, hoodies and long-johns. Cotton is great at insulating but terrible at breathability. Cotton will hold onto any sweat or rain you come into contact with and then become clammy and heavy. It’s generally best to avoid cotton base layers if at all possible. 

Silk is a nice lightweight base layer. Silk has great insulating and wicking properties and feels really nice next to your skin to boot. A problem with silk is that with such great insulating properties, it can be a little too much if you’ll be transitioning from active to sedentary movement throughout the day. Silk is best used for hand, foot or head coverings underneath shoes or a helmet. 


Bamboo is a new player on the scene and was intended to mimic the effects of merino wool while being even more antimicrobial and sustainable. Bamboo base layers are a tighter fit than merino base layers, and a great benefit of bamboo is the lack of skin irritants. For people allergic to wool, bamboo is a safe alternative. 

banboo material
merino wool

Merino Wool 

If you think ‘thick and heavy’ when you hear the world wool, you aren’t thinking of merino. Merino wool base layers are a lighter than sheep’s wool and make a great warm, lightweight and breathable fabric that is also natural. Merino wool still has the insulating and wickability properties of sheep’s wool and is a great choice for colder climates or those whose work requires heavy activity with lots of sweat. 


Synthetic base layers are made from a variety of man-made materials. Polyester and polypropylene are two of these materials. Synthetics are excellent at wicking moisture away from the skin while still managing to dry extremely quickly, keeping you dry and comfortable during your activities. 

The downside to synthetics is that while they wick away moisture, they do hold onto odour. A synthetic base layer might be best for a short work shift or for hours in which you won’t be doing a lot of heavy activity but need the warmth of a base layer under heavier outer clothing. Expect to do laundry more often if you choose to go synthetic. 

synthetic cloth

Why Choosing the right fit is Important

The considerations to take into account when shopping for a good base layer are fabric, weight, friction and fit. We’ve already covered the various fabric types. 

When it comes to weight, you’ll need to look to your specific work and climate requirements. In a hotter climate, choose a lightweight fabric like synthetics or silk. In moderate climates, a light base layer with a heavier outer layer would give you flexibility for changing weather. In super cold climates, go with a heavier base layer like merino wool, a midlayer and a super insulating outer layer, possibly with a waterproof shell. 

Friction is important for your comfort. You want a fabric that slides against your skin rather than catching and irritating you while you’re trying to work. You also want to look to the seams as you don’t want these rubbing either; the least number of seams possible is best, and any seams that are present should be flatlock to give the seam a low-profile. 

When it comes to fit, you’re in luck with base layers; they need to be skintight and that’s about the only fitting requirement. It should follow the contours of your body, but also move with you; you don’t want it to be a struggle to get into the garment, as this is a sign it’ll be uncomfortable to wear. 

For tops, you can choose your normal t-shirt size; base layers will be tight by design. A long hem is a good idea to tuck into lower layers. You can choose your standard size for bottoms too. Make sure they reach all the way to your ankle. 

Compression garments are designed to improve the rate of fresh blood delivered to your muscles and speed the rate of deoxygenated blood back to the heart. Encouraging the flow of blood in this way increases recovery speed on fatigued muscles and reduces risk of energy. Compression garments accomplish this by increasing pressure on your extremities, reducing this pressure gradually back toward your heart. Not all base layers use compression technology. .

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The original technical Helly Hansen base layer. An iconic design with the classic stripe along the sleeve. This long-sleeve base layer top for men provides moisture management and is comfortable and functional as an insulating layer for everyday use, featuring cuffs and a regular fit.

The HH Lifa® construction with 100% Lifa® is a quick-dry, extremely breathable and super-lightweight high-performance base layer. 

The Helly Hansen LIFA works great at keeping you dry and warm. The synthetic fabric is designed to wick away moisture and it does its job with ease.

This base layer works especially well in the 5°C-15°C range, and the wicking properties are so good that this base layer would work great even in a light rain. Use this base layer on its own or paired with heavier insulating layers in cold weather. 

The body is slightly on the short side, so it’s recommended to choose one size bigger than what you would normally wear. 


  • Works very well keeping you dry and warm
  • Wicking property is awesome
  • Works well in the 5-15°C range. It’s especially good in light rain


  • Recommend getting at least 1 size bigger than you normally wear
  • Little shorter in the body than expected

The Under Armour HG is a synthetic version made with HeatGear fabric. Comfortable enough to be worn all day or during strenuous activity, the HG utilizes compression technology for that second-skin fit to keep you warm and dry. 

Mesh panels under the arms and on the back of the neck ensure comfort and breathability no matter what your work shift requires of you. 

The Under Armour Moisture Transport System wicks the sweat away from your body to keep you dry. The 4-way stretch fabrication means the fabric will move with you and allow for greater mobility. 

If you’ll be working outside, the UPF 30+ sun protection is a great perk to this shirt. The HG keeps its shape even after months of wear and is super lightweight which makes it perfect to wear under a t-shirt during warmer weather.

Be sure you like compression technology before you buy; the ultra-tight fit isn’t to everyone’s liking. 


  • Keeps its shape even after months of wearing
  • These fit perfectly for just wearing underneath a shirt when its not very warm
  • Very lightweight


  • UA Compression is not to everyones liking
  • If you’re slightly over padded, it can be a bit unflattering

The Brass Monkeys Merino Wool base layer is made in New Zealand from ethically sourced, natural materials. Merino wool is super soft, and this shirt will feel great against your skin, which is especially nice for a long night at work. 

Brass Monkeys uses really high-quality materials, and this shirt will last a long time and be wrinkle-free, too. The fit is extra tight, with a long tail; this could be a plus or minus, depending on your needs. The V-neck also might be great for some people and not so great for others; if you are layering underneath a t-shirt it might help your skin breathe, but on it’s on might contribute to a cold chest. 

Merino wool has natural wicking properties to keep you dry, and wool is odour resistant, which gives this shirt a leg up over the synthetic options on this list.


  • The quality of material is great and because it’s merino it doesn’t wrinkle
  • Fits well under clothes and is really comfortable
  • Natural fibres


  • Non Compression Shirt

The TCA SuperThermal is another synthetic option. It’s made with flatlock seams to eliminate skin irritation. Mesh panels ensure airflow while the moisture wicking fabric will keep you dry, warm and comfortable.

The soft brushed inner fabric locks in heat for extra warmth. The sizing runs small, so order a size up if you go with this option. All the attention paid to the construction and materials in this fabric make it an excellent choice for comfort during long shifts, and it will work really well for cold weather paired with a jersey or lightweight jacket. 


  • Eliminates chafing due to the skin tight fit
  • Vent panels are great to moderate your temperature
  • Will work well when it really gets cold when adding a jersey or a lightweight jacket


  • Sizing is unreliable (Medium is only a 32/34″ chest UK mens medium is usually 38~40″)
  • Doesn’t have a brushback finish on the inside of the garment

The Sundried Training Top is unique; it’s made by hand in Portugal from high-quality synthetic fabrics. The company practices low-carbon, ethical construction techniques, making this a guilt-free option when you’re looking to build your work wardrobe. 

The sweat-wicking technology prevents chafing by keeping your skin dry, and the fabric dries super-quick, so you don’t get sweat marks.

The construction is seamless, without uncomfortable side seams to rub and irritate. 

Despite being made from synthetic materials, Sundried has constructed this base layer with anti-odour technology to prevent the growth of microbes. With this top you get the best of both worlds; lightweight synthetic fabric without the quick accumulation of odour. 

The shirt runs small, and there are currently only two sizes offered, so choose carefully if you go this route.


  • Impressive quality, ethical brand
  • Sweat-wicking technology keeps skin dry and prevents chafing
  • Hand Made


  • Smaller than expected
  • Only 2 sizes currently offered

The Nike Cool Compression t-shirt comes from a name brand you can trust, with the classic swoop embroidered on the chest. Ergonomic seams and compression technology provide a tight-fit and natural comfort.

Made with flat seams to avoid irritating chafe, the mesh panels at the back allow for breathability. The dri-fit fabric wicks away sweat to keep you dry. 

This shirt could almost pass for a regular t-shirt, which could be a great choice for a night at work when you want to look casual yet still be ready for any strenuous work duties or cold environment.

The shirt runs long, which is great for tall men, but the white version is so thin to be almost see-through, keep that in mind when ordering. 

Whether you work mostly out-of-doors or go in and out of a building all day, and whether you are in a hot or cold climate, you’ll want a good base layer to ensure your comfort.

A proper base layer will keep you warm and dry through anything your work shift might call for, so you can concentrate on what’s important.


  • Lot of compression layers can be on the short side but this one is a good length
  • Good wicking technology
  • Tight yet manoeuvrable and very durable


  • White version is so thin it’s see through 



How could we pick out of these excellent six Thermal base layers, The Sundried Long Sleeve top is made by hand, by an ethical low carbon company, but only comes in 2 sizes. The TCA Mens SuperThermal Top has ‘vent panels’ to moderate your temperature, but is un-reliable in its sizing.

The Brass Monkeys Merino Wool V neck is made with 100% Merino wool, a lighter, warmer, more breathable wool material from New Zealand, the only draw back is that it’s not a compression shirt and is a V-nack. The Helly Hanson LIFA T shirt is designed for the 5°C-15°C range with LIFA quick drying construction, but if you are tall this may run a bit short.

Our last two are the Under armour long sleeve shirt, that’s very lightweight and made with heatgear fabric, sometimes the UA compression isn’t to everyone liking and our Winner is the Nike cool Compression t shirt, it is a good length compression shirt, with good wicking properties, from a brand that you can trust. This is an excellent base layer to keep you Dry and Warm throughout the year, be careful if you are buying the white version though!