Mountain Hardwear Phantom 0°F Sleeping Bag
Specifications
| Weight | Packed Size (L) | Warmth Rating | Fill Weight | Fill Power | Fill Type | Sleeper Height | Seasons | Shape | MSRP |
|---|---|---|---|---|---|---|---|---|---|
| 2 lbs 10 oz | 10 | 0°F | 30.5 oz | 800 | Goose Down | Up to 6 ft (Regular) | 4-season | Mummy | $710.00 |
Comfort & Warmth
The Mountain Hardwear Phantom 0°F is purpose-built for extreme cold and high-altitude environments, offering expedition-grade warmth through its 800 fill power, RDS-certified goose down that delivers exceptional loft, thermal efficiency, and long-term resilience. Its ergonomic mummy cut is designed to minimize dead air space without feeling overly restrictive, while the draft collar, insulated draft tube, and four-chamber hood work together to seal in body heat and prevent cold spots. The contoured footbox allows for a natural foot position and preserves loft around your toes - an area especially prone to heat loss. Mountain Hardwear lines the Phantom with soft, lightweight fabrics that feel comfortable against the skin, while the breathable Pertex® Quantum shell balances wind resistance and moisture management to keep insulation dry and effective. With a 0°F Temperature Rating, and range well into subzero temperatures, and thoughtful design touches for all-night warmth, the Phantom 0°F is engineered to keep you protected and comfortable through the most demanding winter and alpine expeditions.
Weight & Packability
The Mountain Hardwear Phantom 0°F delivers extreme cold-weather protection in a package that remains impressively light and packable for its warmth rating. Weighing 2 lbs 10 oz for the regular size, it’s significantly lighter than many other expedition-grade 0°F bags, thanks to its high-loft 800-fill-power goose down, which provides exceptional warmth-to-weight efficiency. The premium Pertex® Quantum shell not only keeps weight down but also allows the bag to compress efficiently, fitting into the included 12-liter compression sack (compressed down to 9.7L) for easier packing on winter or high-altitude trips. While bulkier than a three-season bag, its balance of subzero warmth, low weight, and manageable packed size makes it a strong choice for mountaineers, winter backpackers, and anyone needing reliable insulation without an unmanageable load.
Price
With a retail price of $710 (regular size), the Mountain Hardwear Phantom 0°F sits firmly in the premium alpine gear category, reflecting its high-end build and near-expert performance. While the cost is steep, it brings serious value for winter adventurers by offering lightweight 0°F protection thanks to lofty 800-fill-power down, a minimalist yet durable shell, and technical features like a draft collar, contoured hood, and precision baffle structure - all designed for sub-zero comfort on demanding expeditions. For those who trek in bitter conditions and need a gear piece that performs reliably under cold, high-altitude stress, the Phantom 0°F justifies its premium price as a long-term investment in warmth and durability.
Quality & Materials
The Mountain Hardwear Phantom 0°F is built with expedition-grade materials and craftsmanship designed to perform in the most demanding alpine and winter conditions. Its insulation comes from 800-fill-power goose down that is Responsible Down Standard (RDS) certified, ensuring both ethical sourcing and premium loft for exceptional warmth-to-weight efficiency. The Pertex® Quantum shell fabric is ultralight yet highly durable, offering excellent wind resistance and a water-repellent finish to help keep the down dry and maintain thermal performance in damp environments. Inside, a soft, breathable lining enhances comfort, while precision box-baffle construction prevents cold spots by keeping the down evenly distributed. Key warmth-retaining features such as a draft collar, insulated draft tube, four-chamber hood, and contoured footbox are integrated seamlessly to enhance durability and comfort over years of heavy use. Premium touches like an anti-snag #5 zipper with glow-in-the-dark pull, dual ventilation capability, and a cushioned face gasket reinforce its thoughtful design. This combination of top-tier materials, technical design, and meticulous construction makes the Phantom 0°F a trusted companion for serious mountaineers and winter expeditionists.
Consumer Sentiment: Pros & Cons
Pros:
- Exceptional warmth-to-weight ratio
- Compressor-friendly packaging
- High-quality construction
Cons:
- Narrow fit may feel restrictive for restless sleepers
- High cost compared to less-featured or synthetic alternatives
Comparison to Comparable Items
NEMO Disco 15: The Disco 15 is roomier and packed with comfort features for side sleepers but can’t match the Phantom 0°F’s extreme cold-weather capability or warmth-to-weight efficiency.
Feathered Friends Hummingbird UL 20: The Hummingbird UL 20 is far lighter and more compact for three-season use, while the Phantom 0°F is purpose-built for subzero expeditions with significantly more insulation.
Western Mountaineering MegaLite 30: The MegaLite excels as a lightweight, roomy three-season bag, whereas the Phantom 0°F is a heavier, premium choice for winter and high-alpine conditions where deep cold protection is essential.
Who It’s Intended For
This bag is ideal for serious cold-weather backpackers, ski tourers, mountaineers, and thru-hikers venturing into sub-freezing terrain. It suits side or back sleepers using insulation pads and layering systems who don’t mind a snug fit. For summer enthusiasts or ultralight minimalists focusing on sub 20°F packs, it may be more than you need - but for winter-grade field performance, it’s a top-tier foil.
