Warmer Baselayers

Baselayer tops have a tough job, particularly in winter – they need to keep you warm when stationary and prevent you from overheating when working hard. Moisture-management is key; sweat needs to be removed from the skin efficiently and cotton T-shirts have long been derided for UK outdoor use with good reason – when sweating the moisture tends to soak into the garment and stay there. That’s fine if you keep moving and generating heat, but when stationary a sodden T-shirt is less than ideal. The same also applies for moisture reaching the garment from the outside – getting caught in the rain in your favourite Thomas the Tank Engine T-shirt is never fun.

In this review I’m going to look at a load of far more suitable baselayer tops aimed at cold-weather use – slightly heavier-weight fabric and definitely long-sleeved. I prefer a zip-neck year round to facilitate venting and am also partial to well-designed thumb-loops to plug the gap between sleeve and glove.


The main issue with synthetic baselayers is their tendency to develop an unpleasant smell over time. Mine generally last a day before the people on the bus start to look at me strangely. There have been many attempts to solve this issue through the use of fabric blends and the addition of substances to destroy the odour-producing bacteria, but nothing really works that well. Other than that, synthetic baselayers are relatively cheap, dry quickly and as the fibres have been specifically engineered they transmit moisture particularly well.

Berghaus Men’s Active Thermal Long Sleeve Zip Neck T ShirtRRP £50

Berghaus have attempted to solve the odour issue through the use of ‘silver ion technology’. It works OK – I can manage a couple of days now without making old ladies faint, but eventually a slight smell is noticeable. The fit is snugger than the image on the left suggests (baselayers work better if they’re close-fitting) but avoids the painted-on effect through a good cut and fabric.  The raglan sleeves are nice and ensure that there isn’t a seam running across the shoulder, though I’m not sure I like the aesthetics of the profusion of white flatlocked seams. I like the cuffs – they seal nicely and are easy to manipulate over watches and above elbows for temperature regulation. The deep front zip allows me to display my medallion as well as vent effectively and the collar is high enough to protect without throttling. Oh, and the zip doesn’t catch on my beard which makes me happy.

Female equivalent? Yup: Berghaus Women’s Active Thermal Long Sleeve Zip Neck T Shirt.

Materials:  Argentium Thermal Grid: 92% polyester/8% Elastane with silver ion technology  Weight: 320g (size L)

Columbia Men’s Baselayer Midweight LS TopRRP £50

I wish I had a better photo of the inner surface of this baselayer – the main torso (blue fabric) is coated in silver reflective dots that form Columbia’s Omni-Heat system designed to reduce thermal radiation, whereas the underarm (black) area is a thinner, high-wicking fabric known as Omni-Wick. This works – the underarm panels DO transmit moisture well, and the increased stretch allows for a totally unrestricted range of movement. It’s hard to assess the effectiveness of the silver dots (I fancy cutting it in half and sewing it to a non-Omni-Heat baslayer) but I like the theory. Although treated with an antimicrobial agent this really is a day-walk baselayer unless you camp solo. I much prefer a zip neck too, and thankfully one is available.

Female equivalent? Yup: Columbia Women’s Baselayer Midweight LS Top

Materials: 86% Polyester, 14% Elastane Weight: 202g (size L)

Marmot Midweight Crew LSRRP £40

A chunky midweight garment such as this colourful effort from Marmot is ideal when worn as a second baselayer under a softshell. With a slightly-fleecy grid-patterned inner face it wicks superbly despite the thicker fabric, but I wish they’d sent me the zip neck version. Again, the flatlocked seams are highlighted with a contrasting thread for some reason – it must be a fashion thing (I think I’m getting old). It’s worth mentioning the length of this top: as a tall size L it’s just long enough to enable me to bend over and reach above my head, and it’s the same story with the sleeves which are on the limit. I’m not too impressed with the cuffs which have a tendency to gape, but at least they can be rolled up above the elbow nicely.

Female equivalent? Yup: Marmot Women’s Midweight Crew LS

Materials: Polartec Power Dry: 96% Polyester (29% Cocona), 4% Elastane  Weight: 189g (size L)

Odlo EVOLUTION WARM LS ½ zip ShirtRRP £65

I’m pretty sure this isn’t aimed at the typical British hillwalker. Even in XL it is somewhat snug on me (it’s a very good thing I used stock photos) but this skin-tight fit does enable the various fabric technologies and anatomical zones to work effectively. There are so many different fabric zones, each with a slightly different construction designed for maximum thermal regulation. And it works. The beauty of synthetic baselayers is the ability to engineer a garment for maximum performance (and price it accordingly) and this is a real example of a performance baselayer. The lighter areas are constructed with an open weave that permits easy wicking, and these areas are also present at the lower back and shoulder blades. I tend to sweat across my chest, and a grid of small perforations aids wicking here. It has a very complicated design, but it’s clear a lot of though has gone into the Evolution Warm and it has paid off. It’s even got a little house for the neck zip.

Female equivalent? Yup: Odlo EVOLUTION WARM LS ½ zip Shirt (women’s)

Materials: 60% Polyester, 34% Polyamide, 6% Elastane  Weight: 202g (size XL)

Paramo Mountain Pull-OnRRP: £62.50

Despite appearances, the Mountain Pull-On is actually quite a complex and well-designed baselayer for the UK hillwalker. The cut is typically Paramo – no attempt at tailoring or niceties, just pure function. As the high weight testifies, this is a thick, warm top, ideal for Scottish winters thanks to Paramo’s proprietary Parameta S reversible fabric which is fleecy on one side and smooth on the other. Paramo suggest that when working hard the smooth face is worn next to the skin to retain moisture and permit evaporative cooling, whilst in colder conditions the fleecy face is worn on the inside to trap air and keep you warm. This configuration also whisks moisture away from the skin, where it can spread out and evaporate from the shiny face fabric. I must admit, I rarely wore the smooth surface next to the skin, preferring the rapid moisture transfer afforded by the ‘cold weather’ configuration which is amazingly effective. If only people didn’t laugh at me when I’m wearing it.

Female equivalent? Nope, unisex.

Material: Parameta S Reversible: 100% polyester  Weight: 357g (size L)

Patagonia Men’s Capilene 3 Midweight Zip-Neck RRP £55

Walkhighlands Recommended
Patagonia isn’t referred to as ‘Patagucci’ for nothing, and this is not a cheap baselayer. But like a Gucci suit it’s effortlessly stylish and extremely well implemented. Capilene baselayers are available in four fabric weights, ranging from Capilene 1 ‘silkweight’ to Capilene 4 ‘expedition weight’. Capilene 3 is ideal for most Scottish cold weather hillwalking. I consider this the synthetic baselayer that all others should be judged against; it’s simple, functional and actually looks quite good too. The dimensions are good – sleeves appropriately long and able to be pulled above the elbow without gaping, and no cold spots when reaching up or bending over. The zip is deep enough to enable me to do my famous Tom Jones impression (circa Las Vegas 1967) and there’s really nothing I don’t like about it. In addition, over half of the polyester used is made from recycled plastic bottles and once worn out Patagonia will take the top back for recycling into new baselayers.

Female equivalent? Yup: Patagonia Women’s Capilene 3 Midweight Zip-Neck

Materials: 100% polyester (51% recycled)  Weight: 265g (size L)

Ussen Baltic Norj Zipped ProRRP £33

If it’s seriously cold the British Army turn to a classic Norwegian Army shirt lined with cotton terry loops and a lovely turtle neck arrangement. Cotton makes them quite cheap to produce, but as discussed cotton is not an ideal fabric for outdoor use. Ussen have taken the classic design and constructed a far more useful and seriously warm winter baselayer. Polypropylene has been used in baselayers for years and it works, wicking well and drying fast, but can get a bit odorous. The tough, no nonsense fabric had a cosy brushed inner, and just the right amount of stretch to keep the fabric hugging the body. The length of both body and sleeves is perfect, with no chance of cold spots and I particularly like the double cuffs which can be folded down to reveal thumb loops. It’s great to see Ussen manufacturing their products in the UK too.

Female equivalent? Nope.

Materials: 100% Polypropylene  Weight: 277g (L)


Merino and merino blends

Despite wool being used in outdoor clothing for centuries, merino baselayers have only really leaped into the public spotlight in the last couple of decades. It’s naturally anti-microbial which means it won’t smell (unlike the wearer sadly) and feels great against the skin thanks to an absorbent fibre core and hydrophobic outer. This unique construction means the fabric remains warm when wet, as a significant proportion of the moisture is contained within the core of the fibre. But merino is expensive and not amazingly durable. In addition, the natural absorbency means that merino baselayers can take a while to dry when wet (but when a soaking is inevitable it’s better to be warm and damp). Manufacturers have attempted to address these shortcomings through the addition of various synthetic fibres in order to create the ultimate baselayer fabric.

Chocolate Fish Taranaki 190 Merino Baselayer Long-Sleeve ZipneckRRP £75

Walkhighlands Recommended
If the Patagonia Capilene series is my baseline synthetic baselayer, the Chocolate Fish range is the merino equivalent. Both the 190 weight and thicker 260 weight offer no frills (such as thumb loops), just the finest merino available crafted into a very well-cut zipneck top. The neck is just on the right side of snug when zipped up fully, similarly the sleeves can be pushed up beyond the elbow without restricting circulation and are long enough to prevent gaps. This also the only baselayer I’ve seen with overlocked or serged seams – they aren’t as aesthetically pleasing to garment designers but feel less bulky than the omnipresent flatlocked method. I can’t even detect the seam that runs right across the shoulder when wearing a pack. Chocolate Fish put a lot of effort into ensuring that their merino is the best available, not just in terms of performance but also sustainability. The garments are actually made in New Zealand, not just from New Zealand merino shipped abroad, and the quality is obvious. I’m a little ashamed to say it, but I’ve been wearing the Taranaki 190 for over a fortnight now and it doesn’t smell. At all. I’m beginning to think it’s witchcraft. My penchant for simplicity might be a bit obvious throughout this series of reviews, but for a hillwalker requiring a basic merino baselayer without the characteristics imparted by synthetics and blends, this is hard to beat.

Female equivalent? Nope.

Materials: 100% Merino Wool Weight:  283g (L)

Helly Hansen Warm Freeze 1/2 ZipRRP £60

Famous for their Lifa series of polypropylene baselayers (perhaps unfairly branded ‘Smelly Hellys) Helly Hansen’s Warm system features a layer of this familiar synthetic as an inner, underneath a fine merino wool outer. This concept sounds promising, making use of the improved moisture transmission of an engineered fabric with the insulation and pleasant finish of merino. It sounds very logical, but in reality I struggled to tell the difference in performance between this and a fully synthetic baselayer. The inner Lifa fabric is very open, leaving the merino outer to function like a scrim over the top. It’s an extremely close fit (I recommend sizing up) which does help with the wicking process, and I love the snug cuffs and good, zipped neck. The length isn’t as generous as some despite a scooped back, and I found the flatlocked seams a bit bulky around the shoulders and armpits.

Female equivalent? Yup: Helly Hansen Women’s Warm Freeze 1/2 Zip

Materials: 57% Merino Wool, 43% Polypropylene Weight:  232g (L)

Icebreaker 200 Lightweight LS Sprint ZipRRP £73

Icebreaker have almost reached the generic stage when referring to merino baselayers, though they have morphed from their humble New Zealand beginnings into a truly international behemoth. Though still based in New Zealand, most products are in fact manufactured in  China on a large scale. However – their environmental and social ethics are admirable, using their clout to influence the way in which the New Zealand sheep farmers are paid and sheep are treated. As a garment the Sprint model is designed for multi-sport use, featuring a nice little pocket at the hip which hasn’t managed to clash with a pack strap yet. The seam running across the shoulder suggests that this isn’t really designed for use with a backpack. The fit is loose, but sizing down to get a closer fit may result in a loss of length at the back and sleeves. As it is, my size L is a touch too short. The sleeves are also loose, not helped by a thick band around the cuff which encourages gaping. I’m pleased that there are thumb loops, but I’d prefer a tighter seal instead. Perhaps not ideal as a hillwalking baselayer, but I quite like the styling and fit.

Female equivalent? Yup: Icebreaker Women’s 200 Lightweight LS Pace Zip

Materials: 97% Merino Wool, 3% Elastane Weight:  305g (L)

Rab MeCo 165 Long Sleeve Zip TeeRRP £65

Walkhighlands Recommended

I think Rab might have discovered the optimum merino/synthetic blend with the MeCo baselayer. Rather than combining merino with new polyester which is petroleum-derived and not amazingly good for the environment, the synthetic element of the yarn is obtained entirely from recycled polyester. This is then fused with Cocona – an activated carbon derived from discarded coconut shells. The theory is that this synthetic content enhances the properties of the wool to create a kind of supermerino baselayer. Where 100% merino can take a while to dry, the Cocona content really does speed things up noticeably. Moisture is almost sucked from the skin and spread across the outer surface for effective evaporation. Where other blends tend to negate the natural anti-bacterial properties of merino, the activated carbon in Cocona seems to enhances it by absorbing odour. Coupled with this amazing fabric the garment itself is obviously designed for UK hillwalkers with a good cut, long back and sleeves and even a beard-proof zip. Cocona Inc is a private company and I fully expect to see this material creeping into more and more garments.

Female equivalent? Yup: Rab Womens’ MeCo 165 Long Sleeve Zip Tee 

Materials: intimate blended Merino Cocona polyester yarns (65% Merino / 35% Cocona) Weight:  244g (L)


Rohan Men’s Superfine Merino 200 ZipRRP £85

On the face of it there is little to distinguish this from the Chocolate Fish Taranaki top. It’s a wonderfully cosy and luxurious baselayer with all the positive features of 100% merino such as odour-resistance and warmth along with the high price. The merino used is Zque certified which offers assurance that its production is both socially and environmentally sustainable, but I notice from the tag that the garment was made in China from Australian wool. The top uses flatlocked seams which are low profile but contain a lot of thread. The seam running across the shoulder (although slightly displaced) is therefore quite noticeable when wearing a heavy pack, and I don’t understand why raglan sleeves were not used. The cuff is great – nice and wide with a thumb loop that doesn’t put stress on the shoulder seams when in use, and there’s enough stretch to allow the sleeves to be pulled up for temperature management. The zipped neck is good, and the cut superb – the colour and styling make this a great everyday or travel shirt as well.

Female equivalent? Yup: Rohan Women’s Superfine Merino 200 Zip

Materials: 100% Merino Wool Weight:  306g (L)

Agree with Phil? Let us know what you think on our forum.

Enjoyed this article or find Walkhighlands useful?

Please consider setting up a direct debit donation to support the continued maintenance and updates to Walkhighlands.

Share on 

Walking can be dangerous and is done entirely at your own risk. Information is provided free of charge; it is each walker's responsibility to check it and navigate using a map and compass.