But you can revert law of nature.
1 Few Of the Points to keep your water flowing in harsh environment
2 Fill your reservoir with warm (but not boiling) water, which will
take longer to freeze.
3 Drink frequently (a sip every five minutes or so) to keep your water
circulating.
4 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.
5 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.
6 Our winter packs also feature insulated drinking tubes, and many of
the smaller packs are designed to fit both under and over your
jacket.
7 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