1.)SOURCE seals its entire WINTER KIT PLUS systemreservoir, insulated hose, and bite valveinside a zippered mitten of closed-cell foam. Though you can slide the kit into a pack,
Insider Beta: Winter Hydration
Use the following tips to keep your H2O liquid longer: 1. Before setting out for the day, fill your reservoir or bottlecarefully!with near-boiling water. (Check your user manual first.) 2. Moving water is slower to freeze: Sip frequently to keep it circulating. 3. The hydration tube is your system's most freeze-prone point. Keep it clear: After every sip, blow excess water back into the bladder.
we suggest you slip on the attached bare-bones shoulder straps and wear it under your shell. Why? When chilled inside a backpack at ten degrees, the swaddled hose and valve resisted freezing for 30 minutes but seized up after an hour; body heat will extend that window considerably. The reservoiravailable in 67 or 100 ouncesis excellent, thanks to a glasslike polymer interior that inhibits grunge buildup. ($40; 303-417-0301, www.sourcevagabond.com)
2.) The HYDRAPAK SNOWSTORM fights off Mr. Freeze with a neoprene-covered hose and a capped bite valve. Once we pried off the frozen nozzle cap after an hour at ten degrees, the Snowstorm kept the water comingbut it was the consistency of a Slush Puppie, well on its way to ice. That's probably because the 100-ounce bladder, while buried deep in this daypack, is uninsulated. While the roll-top reservoir was easy to fill and clean, the pack's construction felt a little slight for backcountry duty. Stick to carrying snowshoes and lunch and you'll be fine. ($50; 866-549-0559, www.hydrapak.com)