While there will always be a heated debate about what the best hydration system or water bottles for winter hiking are, I think we’d all agree that the minimum requirements for winter hydration are:
- The water you bring on a winter hike can’t freeze
- The warmer the water stays, the better, because drinking cold water in cold weather can chill you
- The bottle cap, hose, or mouthpiece can’t freeze and prevent you from drinking your water
- Your water container should be able to withstand hot liquids
While there are several hydration systems that satisfy these requirements, each of them has pros and cons in different climates.
Hydration Reservoirs and Drinking Tubes
I know many people who use hose-based hydration systems for 3 season hiking and prefer to use them in winter because they lower the barrier to staying hydrated in the drier winter air. If you intend to use a system like this, it’s best to purchase one with an integrated insulation sleeve like the Camelbak Insulated Unbottle.
In addition to reservoir insulation, you’ll want to add drinking tube insulation to your hydration system to keep the hose and mouthpiece from freezing. While this insulation can be a bit tricky to slide onto a drinking tube, it tends to be interchangeable between hydration system brands.
In theory, the body heat that radiates from your back will keep your hydration reservoir from freezing in winter. You can augment this by filling your reservoir with boiling hot water, surrounding it with insulating clothing inside your backpack, or even stuffing a Grabber handwarmer into your pack’s hydration pocket to heat it while you are hiking.
In addition, there is a technique commonly used to keep your drinking hose and mouthpiece from freezing. After taking a sip of water, blow into your drinking hose to push any remaining water in the hose back into the hydration reservoir so it doesn’t freeze in place. This takes some practice to become automatic, but it does help to keep the hose clear, especially if it is wrapped using drinking tube insulation.
If there’s a downside to using a hydration reservoir, it’s that they are difficult to refill with boiling snowmelt on overnight trips without burning your hands or getting your gloves soaked. But provided you are not hiking in very cold temperatures or taking extremely long day hikes, a hydration system can be adapted successfully for cold weather use.
Nalgene Bottles
Wide-mouth Nalgene Bottles (32-ounce) are also a very popular choice for carrying water in winter because they can safely hold hot liquids, they’re easy to refill and clean, easy to drink from, and most hikers have a few sitting around the house already. I prefer using the milky white 32 oz. Ultralite Nalgene bottles because they’re lighter weight than transparent ones.
It’s best to insulate a Nalgene bottle with a neoprene or insulated sleeve if you carry it on the outside of your backpack, in a pocket, or clipped to a strap. If you fill the bottle with boiling water, it will remain warm for a few hours. With all water bottles, it’s best to use wide-mouth ones in winter so that ice doesn’t form in their neck and to store them upside down to prevent the threads from freezing.
Alternatively, you can carry all of your water bottles inside your pack and insulate them with your extra clothing. Doing so will keep them much warmer and for much longer, but it takes more discipline to stop, open your pack, and have a drink periodically. Prehydrating before a winter hike is a good way to get a head start on this and can reduce the amount of water you need to carry.
I carried a Nalgene bottle in an insulation sleeve on the outside of my backpack for many years and stored the rest of my bottles in my pack, swapping them out during the day. It’s a functional approach to winter hydration if you have a backpack with pockets that are reachable and large enough to hold a one-liter Nalgene bottle in an insulated sleeve.
However these days, I keep all my water bottles inside my backpack because they stay warmer longer. I have a drink whenever I do a layer change, eat a snack, admire a view, consult my map, or take a short break. When I do drink, I try to consume a half-liter at a time, which makes it easy to keep track of how much water I have left.
If there’s a downside to Nalgene bottles it’s that you often need to take your gloves or mittens off to open them which can be clumsy due to the lid-keeper strap unless you cut it off. It is also possible to crack Nalgenes made out of hard plastic, so you should use the white Nalgene bottles made out of high-density polyethylene, if possible. They’re a lot less expensive too.
Metal Bottles
I’m not a fan of insulated metal bottles for winter hiking and think they’re a bad choice because they’re too heavy to carry. This matters less on a short winter hike, but if you have to carry three liters of hot water on an all-day hike, the added weight can make a difference. For example, a 32 oz insulted Hydroflask bottle weighs 19.2 ounces empty. Compare that to a 32 oz Ultralite Nalgene Bottle that weighs 3.5 oz. That difference adds up when you have to carry three liters of water for a hike that lasts eight hours or more.
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