Peter Grove Sørensen and Benjamin Kjær Harregaard applied to our Field Test program with a plan of hiking 600 kilometers through the Pyrenees: from the Atlantic in the west, heading east towards Andorra. They never set an endpoint, they just walked as far as they wanted to. It turned into 20 days in the middle of the heatwaves that plagued Spain over the summer.
Two tops for twenty days
Peter has hiked long distance for years, and he has spent that time cutting things away. His principle is that gear has to do more than one job, because the lighter the backpack, the more kilometers are left in the legs.
He used two tops for the entire trip. A sun-protective hoodie to walk in when the sun was at its highest. And the LOOW merino T-shirt.

The landscape changes under your feet
The Pyrenees run like a wall between Spain and France, from the Atlantic to the Mediterranean. Walk them lengthwise and the weather changes several times along the way.
In the west lies the Basque Country, where the air comes in from the Atlantic and keeps the mountains green. Further in it gets high and rocky, and the nights turn cold, even in the middle of summer. Towards the east, in towards Catalonia and Andorra, it gets dry in a completely different way.
That variation was what they applied to test in: cold nights, scorching days and everything in between. This year they got more of the hot end than anyone had counted on.
The layer you put on when the day is done
While actually walking in the sun, Peter wore the hoodie. The T-shirt was what he changed into afterwards.
It was very liberating to put on after such a long hike in the sunshine, when you were all sticky and salty. It was nice to just be able to wash up in a river and then put this merino wool T-shirt on, which could keep you nice and cool and comfortable in the evening hours.
At night it sat between him and the sleeping bag. His own summary: he never froze at any point.
It also got a third role, which he calls the civilized layer. On rest days, when they came down and had to be among other people, it was the one he put on. It did not smell, and it looked presentable.
The fever in the tent
Somewhere up in the mountains, in thirty-degree heat, Peter got a fever. He had to stop and lie down in the tent while the sun beat down on the canvas.
There it simply helped keep me cool, even though the sun was beating down on the tent. So it was also my recovery layer when I was really pushed and really sweaty and had a fever up in the mountains.
When he later had to put it into two lines, it came out like this:
It saved and cooled my ass when I was down with a fever in the middle of nowhere under the burning Spanish sun.

Twenty days without washing
One advantage of clothing in 100% merino wool is its ability not to develop odor.
During the 20 days my friend and I were hiking, I didn't wash the T-shirt at any point. Despite that, it didn't start to smell at all.
He traveled down to the Pyrenees in it, wore it for twenty days, and traveled home to Denmark in it again. Unwashed the whole way.
A detail worth knowing
Peter went one size up because he likes his clothes loose. That is not an objection to the fit, it is a choice. But it is worth knowing if you are choosing for yourself: our 135 gram sits fairly close to the body by default, to keep it comfortable during physical activity.
The T-shirt is coming along again, he says. He has bikepacking trips in the calendar for the autumn, the spring and next summer.
About Field Test
Peter is one of twenty-five who brought a T-shirt into the field this summer. The deal was simple: wear it the way you wear clothes, and tell us what you experienced. Nothing else.
The stories come from mountains, from a fire station, from an emergency ward and from an abandoned coal mine on Svalbard. We will share them through the autumn.