Mountain Hardwear Phantom 0/-18 sleeping bag review: a winner for winter

First impressions

Mountain Hardwear Phantom 0/-18 is the flagship sleeping bag in the Mountain Hardwear line. As it's name suggests, the Phantom 0 offers warmth down to a bone-chilling -18°C. Yet, given its four-season capabilities, it is lightweight and compact, with an impressively small pack size that ranks among the best in this class. It is filled with a hefty 850g/1lb 14oz of 850 fill power down, housed in either a Pertex Quantum or Gore-Tex Windstopper fabric shell.

The fit is highly tapered to maximise thermal efficiency. As such some might find it a little restrictive, though at high altitudes or low temperatures you’ll appreciate the extra warmth.

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The one rather surprising omission is that the down fill has no hydrophobic treatment, though arguably the highly water-resistant outer renders this unnecessary.

In the field

In full winter conditions, being zipped up in this bag as your breath condenses in the chill air of your tent is a wonderful sensation. It does a great job of locking in vital warmth thanks to a well-designed neck baffle and vertical box-wall chest baffles to counter down migration, which could otherwise cause cold spots.

The footbox and panelled hood are similarly well-constructed. To be honest, there’s little to fault. So if you’re a serious winter camper, you might consider this tried-and-tested four-season down bag for your next adventure.

Similarly, if you’re heading off on a trekking or mountaineering expedition at higher altitudes, it’s a good choice to take with you. Otherwise, in all honesty there’s a good chance that a bag delivering this much warmth will be overkill.