1) Add some Na containing electrolyte or other Na containing drink or Na containing food to the water. Salty water is harder to freeze solid as it affects the ability of the molecules to bond. As previously noted, H2O hydration can be neglected in winter. We shouldn't assume hydration is only necessary in hot weather or when sweating profusely.
2) Surround with any insulation I'm carrying(spare socks, jacket, shirt, etc) usually inside but not always in the pack when on the move. It helps keeping water liquid if in the pack, which provides some insulation in itself, adding insulation in the form of a spare merino sock, shirt, jacket, etc and accustomed to being a hiker rather than camper as our bodies generate heat that's transferred to the inside of the pack.
3) If needing to insulate a round Nalgene or Smart Water type bottle I've seen a few winter backpackers/winter outdoor enthusiasts use foam copper pipe insulation that is already slit cut to the bottle's length, adding a piece to each side of the bottle, and then a few wraps of duct tape/etc. I've seen the same done with a piece of Reflectix R21 or Cool Shield Thermal Bubble Wrap, the same stuff some use as added under sleep system insulation.
Hmm, maybe they'll use this info in Backpacker or Base Camp this fall/winter?
Last edited by Dogwood; 07-09-2019 at 22:12.
You simply don't add that much salt to drinking water that makes it undrinkable just as we do in summer STILL enabling hydration...while also reducing or watching Na in food and possibly other dietary sources. Quite a few packaged backpacking meals and trail snacks are super high in Na. The salt is added only in a small amt slightly depressing the freezing pt while also aiding in mineral replacement which is always needed even in winter not eliminate the freezing pt. Stored inside the center of a backpack further insulating the water with clothing CUMULATIVELY works. The NaCl does not have to be a magic single bullet approach. Adding Na is a component of reducing freezing drinking water. Indeed, if adding Na to a 3%+or - content the drinking water causes bodily problems such as the case.
What you said is true too. Just offering some DIY contextual details to cumulatively consider.