Answer

Our reservoirs are designed to be rugged and durable enough for almost every environment—but they’re not much use if the water inside them is frozen.
Here are a few more tips for keeping your water flowing in frigid temperatures:

• Fill your reservoir with warm (but not boiling) water, which will take longer to freeze
• Drink frequently (a sip every five minutes or so) to keep your water circulating
• Blow back into the drink tube after you take a sip. This will clear water from the narrowest parts of the reservoir (like the bite valve and tube), which are usually the first to freeze
• Keep your water supply close to your body by wearing your pack under your jacket and routing your drink tube under your arm or through your pit zip. Our winter packs also feature insulated drinking tubes, and many of the smaller packs are designed to fit both under and over your jacket
• On overnight trips, sleep with your water to keep it from freezing overnight. Just lock your bite valve closed and then stuff your reservoir into the bottom of your sleeping bag

While we work tirelessly to make our reservoirs as reliable as possible, we can’t change the laws of nature: in extremely cold temperatures, your water might freeze anyway. For that reason, it’s good to carry a backup bottle with a larger mouth opening, like the Chute.