At USWE®, we like to challenge ourselves. Above all, we're triggered by successfully doing things that no one has done before. Therefore, we are pumped to present our unique winter technology called Thermo Cell, which we have developed under very special conditions.


  • Thermo Cell encapsules heat from physical activity in an insulated air pocket.
  • Protects the drink tube from freezing even in the most extreme winter conditions.
  • Technology successfully tested in -26 °C / -15 °F cold temperature.
  • Thermo Cell is included in all USWE Winter Backpacks



During our multi-year collaboration with the traditionary cross-country ski events Vasaloppet® in Sweden and Birken® in Norway, we've had the opportunity to study and interact with thousands of end users. At marathon winter activities, frozen hydration tubes and bite valves is becoming one of the biggest issues for the skiers that use hydration backpacks and hip-packs


An old proven alternative that most people in the industry use, is a type of insulation of the hydration tube like "neoprene / foam sleeve". However, this method does not work optimally when the outdoor temperature drops below -5 °C / +23 °F. No matter how much insulation is used, the temperature drops slowly down the tube, and finally becomes to ice.

So, we've stepped in to make a (real) winter resistant technology.



Large parts of our initial product development phase took place in an old freezer building in the very south of Sweden (Kyrkheddinge), in a closed ice cream factory. For several months, we've been there doing product testing in temperatures below -26 °C / -15 °F to test our various ideas that would prevent freezing ice in tube and bite valves.



From the start we had many creative and complicated ideas on how to solve the tube problem. Some of these were for example an electric heated tube with battery or solar cells, heating pads etc. None of these worked optimally and, on top, it would be far too expensive to produce and sell.


So, we chose a completely different solution, which was sooooo much better, simpler and also environmentally friendly :-).




When it was time to do the fine adjustments on the technology we contacted the legendary Swedish cross-country skier Johan Olsson (2x World Champion 50km). We knew he was meticulous and extremely picky with his equipment, which was a perfect match for our odd project.


The goal was clear, together we would make the world's best winter backpack for cross-country skiing, running and cycling.

Since that day, Johan has been involved in our USWE® testing and design of the backpack. From securing the fit of the harness system when in action, to how the hydration tube and bladder to withstand extreme cold.



”Over the years I’ve been having problems where the tube got frozen on my hydration backpack despite the weather not being too cold. After many attempts on my own where I tried different approaches without a satisfactory result, I had given up the possibility of using hydration backpacks in the winter.


Now when I got to participate in the development of USWE's new winter technology, I feel it’s incredibly inspiring because I'll never need to worry about the hydration getting frozen. In addition, the backbacks are incredibly well made where the fit actually makes me not even think about wearing it when in action”.


-Johan Olsson




The NORDIC backpack is our first winter backpack that’s using our revolutionary Thermo Cell technoloy. The backpacks use body as the heat source and a thin permeable membrane and space suit technology, USWE® has with this solution solved both the insulation and the heat source.


The technology we have developed has been successfully tested in -26 °C / -15 °F cold temperature, with a final result measured at +19 °C / +56 °F inside the Thermo Cell pocket where the hydration tube was stored. It was also used in 2019 at both Vasaloppet® and Birken® by hundreds of end users that bought the bags.


Did it freeze in the tube at all after being in the extreme cold? Absolutely not!



Thermo Cell is equipped with a multilayer insulation cover that reflects the heat on the inside and shields from the cold and wind from the outside. By its design, the Thermo Cell closes tightly to the body and a thin mesh membrane permits maximum body heat to pass through. Used in this way the body heat feeds the Thermo Cell with thermal energy. Smart!

Thermo Cell encapsulates heat from physical activity in an insulating air pocket that protects the tube and bite valve from freezing even in the most extreme winter conditions. Therefore, we have chosen to provide both shoulder straps on the NORDIC, HAJKER and POW backpacks with Thermo Cell so that you get the option of choosing which side you want to have the tube in tube, or having tubes on both sides (double hydration bladders). Or optional, why not store gels and bars that you easily reach on-the-go in the pocket you don't use.



  • Exterior Outer layer: Insulation cover for drink tube & bite valve. Stops all wind speed and keeps the cold out
  • Exterior Inner layer: Heat reflective material with the function of reflecting up to 100% thermal radiation
  • Inside: Tightly sealed mesh membrane that permits maximum body heat




The NORDIC is also equipped with a thermal function for the hydration bladder itself. During the winter, many athletes heat their hydration before the activity to avoid drinking ice-cold hydration. Therefore, NORDIC comes with a hydration bladder that can withstand temperatures up to +60 °C / +140 °F and with an outer layer based on the same technology as Thermo Cell on the front of the backpack.


Heat the hydration to about +35 °C / +95 °F and it stays above +7,5 °C / +46 °F for at least 4 hours. This is the test results in an extreme cold weather of -26 °C / -15 °F.




“What really stands out about USWE's backpacks is the incredible fit. It’s stable and very flexible. The balance in the upper body is extremely important in order to create power down the skis, and then it’s extra important that the backpack is firmly secured without adversely affecting you when you’re in action. In addition, the shell is extremely well made and feels like it can last through all the adventures”

Johan Olsson




In January 2020 we won the Scandinavian Outdoor Award - for our NORDIC backpacks in the hardware category. The motivation from the jury was:

"For high-intensity winter activities such as running, skating, or cross-country skiing, the USWE Nordic 10 pack offers an innovative, easy-to-adjust carry and well-fitting unisex system that allows for a stable, bounce-free and non-restrictive fit. It also has smart features, including an insulated sleeve for the hose of a bladder that is heated up by the body, reflective points, and a durable, snag-free back panel.”


Sustainability info:We are also proud of the Award jury highlighting our take on sustainability with the following words:


"USWE operate with the highest standards of quality to make the products last. They chose to heat the Thermo Cell with body heat instead of replaceable chemicals or batteries and electricity."


Read the full award here