A couple of years ago we visited the headquarters of W.L. Gore, makers of world-famous Gore-Tex and Windstopper products, among others. While touring their research and development facilities, one of the most profound things we learned was how many sweat glands are in the human body, and where they are located. On average, the human body will have anywhere between two million and three million sweat glands. And while most of us might think the highest concentration is found in our armpits, the reality is that your hands and feet contain more sweat glands than any other part of the body. One square inch of the palm of your hands can contain as many as three thousand sweat glands, and your feet contain about 250,000 sweat glands – each!
Let’s apply this to a day of snowmobiling. Over the course of a long day of riding, each one of your feet can produce as much as 1 cup (250 ml) of moisture, as water vapour, per day! Hands don’t produce quite as much, about half of the amount, but when you consider the fact your feet can sweat as much as a cup of water and your hands can sweat a half-cup of water, you begin to realize how important it is to let the water vapour out, and more importantly, start the day with completely dry socks, boots and gloves.
What we see after so many years of snowmobiling is how riders will typically be fine the first day out, but if they don’t get their boots and gloves completely and totally dry over night, their hands and feet get colder much easier the second day out. This also explains why we have such better success keeping hands warm by swapping gloves with a dry pair half way through the day, and using the handwarmers at the lowest setting possible to minimize the amount of sweating from your palms.
We are very particular about using boot dryers and glove dryers at night, so our gear is completely and totally dry for the next day of riding. If each boot just had a cup of water vapor introduced into the liner, it’s going to take some effort to get what’s left in there out of the insulation. And we all should be familiar with what happens when insulation gets wet. This also explains why Merino wool is one of the best fabrics to make socks out of, as wool is one of the few fabrics that retains much of its insulation capability when wet. The difference is significant.
That’s also why you want dry socks each and every day. Do not assume your socks are dry and can be used again, you want a clean and dry pair each and every day. Some riders will even go as far as carrying an extra set of socks with them, as they have learned their feet sweat so much over the course of a ride that they need to swap them out just like gloves. This is an extreme example, but not with gloves. Most of the SnowTech test riders will swap out their gloves half way through the day, just because we can feel them getting damp as the day goes on and when they get damp, keeping your hands warm gets to be a downhill battle as the day goes on. Part of this also is caused by the body reducing blood flow to the extremities (to protect your organs) as the core temperature slowly goes down, but the importance of understanding how much sweat is being produced by your hands and feet can not be underestimated.
Each and every one of our test riders will use two or three boot dryers each and every night. Over the years, we have learned how much of a difference this makes. One boot dryer for the boots, and two of the dryers for two pair of gloves. Some riders will even use two pair of boots, rotating them day to day, so they never wear the same pair two days in a row. It makes a difference to have completely dry gear. Hundreds of thousands of miles after that many years does teach you a few things, and this is one of them that we try to share with anyone that comes with us for test sessions. Again, the difference is significant.
This also highlights the need for fabrics that don’t hold moisture, and the need for breathable gear as well. Having waterproof gear is really nice for snowmobiling, but a plastic bag is waterproof, so why not use something like that to keep the water out? Because it also keeps the water vapor in; it doesn’t “breathe”. That’s where the products like Gore-Tex, and the new kid on the block, Sympatex, come into play. Gore-Tex is a breathable membrane that has holes in it small enough to keep water from getting in, but large enough to let water vapor out. Sympatex is a non-porous membrane laminated to a textile base so it acts more like a fabric, but the basic function is similar. The resulting fabric is tight enough to keep the water out, but breathes to let vapor escape from the inside. Other so-called waterproof products just don’t measure up to these two, in our own personal experience. They might keep water out, but like the plastic bag, they don’t breathe as well as the Gore-Tex or Sympatex products do. That’s why Gore-Tex and Sympatex products are typically going to cost more, but they are better, and worth it, in our opinion.