DILLING Underwear tested on Kilimanjaro

At DILLING, we are convinced that our woolen underwear can keep you warm regardless where you are. Therefore, we recently sent 4 sets of our long woolen underwear with Jan and Mikkel to Tanzania to test if the underwear could keep them warm on their trek to the top of Kilimanjaro.


Father and son tell the story

With just two weeks till our departure, and our bag packed full of gear and expectation, one last package shows up in the mail. The package is from Dilling Underwear and contains 2 sets of ski underwear in exclusive Merino Wool, along with two sets of long underwear with short sleeves in organic Merino Wool. We have received the clothing to test if it can keep us warm, dry, and comfortable, a few day later when we get on a plane to Tanzania to climb Africa’s highest mountain: KILIMANJARO.

With its 5895 meter, Kilimanjaro is the world’s 7th tallest mountain and the tallest free-standing volcano in the world. Making it to the top does not involve and technically difficult climbing, as much as it is a challenging and hard trek. The journey starts at the foot of the mountain at an altitude of 1833 meter, and on our way to the top, we move through five different climate zones. This is the equivalent of going from the Equator to Antarctica in seven days! Since the weather at high altitudes is also quick to change, it is very demanding on our gear and not least our clothing. 

DILLING Underwear tested on Kilimanjaro

The first day’s hike starts at Machame Gate, from where we have a 5-hour hike ahead of up with a good increase in altitude. The temperature is about 25 degrees and the humidity high, as we make our way up through the jungle. For fear of sweating too much in the heat – and thereby getting dehydrated – we have both opted to start the trip in a regular running T-shirt of 100% polyester. For all intents and purposes, the shirt is fine and breathable, but when we stop in the shade, we soon find that we are getting cold in the damp shirt. Therefore, we change into the short-sleeved undershirt of Merino Wool, which, even though it gets damp or even wet, still keeps us warm. The advantage of the wool is that unlike cotton and synthetics still keeps its ability to insulate when wet.

The next three days, we practically live in the short-sleeved woolen shirt that proves perfect, even though the temperature varies between 5 and 20 degrees. When it is windy, we just supplement with a windbreaker - the undershirt keeps us warm close to the body. 

DILLING Underwear tested on Kilimanjaro

Although the day temperatures easily fluctuate up to about 20-25 degrees, the nights on the mountain are cold. Ver cold. Already the first night at an altitude of 3100 meter, we decide to pull on each our set of ski underwear. The ski underwear (long sleeves and legs) feels a bit softer in quality than the normal set of organic underwear. It is not that our other set is scratchy, really – it’s a far cry from the feeling of a knit wool sweater against bare skin! – but the wool fibers are just so fine in the ski set that you can hardly tell you are wearing it. It just feels that so good. At the same time, the set fits more snugly to the body, making it more comfortable when, like us, you have to spend the night in both a sleeping bag and a liner, where the many loose layers easily become irritating and cause you to lose sleep! 

As we gradually reach higher elevations, the vegetation changing and the temperature falling, we put on our organic long johns as a foundational layer under our light trekking pants. The power of insulation is great, and since we are also physically active, we occasionally have to roll up our trekking pants to regulate the temperature around our legs. Even so, we never get the feeling that we are "baking". The long johns are very breathable, and any sweat is quickly wicked away from the body. 

From home, we had each packed our bags with all kinds of different garments, which we imagined we would need. It soon turns out, however, that the organic foundational layer combined with a good pair of trekking pants and a shell is plenty. 

DILLING Underwear tested on Kilimanjaro

It was not until the night to the 6th day, when we had to hike the last stretch to the top, that we chose to double up. The temperature near the top is around -12 to -14 degrees and with the wind chill factor, the temperature can get all the way down to about -25 degrees! Therefore, we put on both sets: the tightly fitting ski set closer to the body, and the looser organic underwear on top. Finally, we are wearing our normal ski jackets and ski pants. 

The first part of the trip is not as cold as expected, and we both start to sweat. Again, the properties of the wool are an advantage, and in spite of two wet layers, we don’t feel the cold at all! Actually, only Mikkel’s feet feels the low temperatures when we approach an altitude of 5500 meter and gusting wind. 

DILLING Underwear tested on Kilimanjaro


When back at a humane altitude a day and a half later, we evaluate the performance of the two sets of underwear:


Both sets have excellent insulating properties, and the respiration is great as well. We were never cold, and although we were physically active and were sweating, the dampness was quickly wicked away from the body. As a foundational layer, the two sets are fantastic, and combined with good hiking pants and shells, regulating our body temperature according to our surroundings and the degree of our physical exertion was incredibly easy and quick.

Seams and joints in both sets are done properly and are not noticeable during use. The products seem robust, although they have good elasticity. As to the fit, the organic set of underwear seems to fit a bit more loosely compared to the ski set, which fits tightly to the body. The bottoms in each set is fitted with a fly, which is a detail you appreciate, when you have to go in the middle of the night when it is minus 7 degrees.

At the same time, there is room in the armhole of the ski set for your thumb, so you avoid having the sleeve crawl up your arm under the jacket. Smart! The comfort of movement in both sets couldn’t be better, and as we have touched on earlier, both products are soft and comfortable, although the wool fibers in the organic set can be felt slightly more.

We have mentioned that the Merino Wool has exceptionally good warming and moisture-wicking properties, and we had heard that the wool should minimize any problem smells, but the fact that our woolen underwear had practically no smell after seven days of constant use - and notably seven days without a bath! – that surprised us.


Donation to the team


We will finish with one last thing, namely a situation that surprised us on our way up the Kilimanjaro, namely the conditions for the hundreds of porters that each day take care of carrying the tourists’ heavy luggage, as well as tents and gear, from one camp to the next throughout the trip. These (mostly) young people are undoubtably the ones who work the hardest on the mountain, and while the rest of us hike toward the top wearing smart, highly technological and ergonomically correct hiking clothes, the porters are usually dressed in regular jeans, cotton T-shirts, and worn-out Converse shoes. The dress is as far from optimal as you can imagine. Getting proper equipment in Tanzania is both expensive and difficult, and for this reason, those who work on the mountain (porters, cooks, guides) depend on donations from tourists like us. Both in form of tips, which is a mandatory part of their pay, but also in form of gear. We personally ended the trip by handing down to our amazing team a good stack of mittens, woolen socks, beanies, thermal underwear, neck warmers, and of course the underwear Dilling Underwear so kindly provided for us to test.

DILLING Underwear tested on Kilimanjaro

So, if you suddenly spot the Dilling brand on your way to Barafu Camp, you will know that there is a guy who isn’t cold!

//Jan og Mikkel Hilgart


Thank you to Jan and Mikkel for their great report. Here you can see the products the two of them tested:

Merino woolen leggings with fly for men, black
Quarter-sleeve Merino woolen shirt for men, black
Long johns for men in scratch-free Merino Wool
Woolen shirt for men for active and home wear
Woolen underpants for men for active wear
Woolen shirt for men for active wear