Therm-a-Rest Boost 650 Down Sleeping Bag 32F
- 32F/0C rated, specs list minus 4 to 0 C
- Up to 10F/6C warmer with WarmZip closed
- 650 fill RDS-certified hydrophobic down
- 2 lbs 14 oz, 85 x 38.5 in
- 14.5 x 7.5 in packed size
- Semi-rectangular, Long Wide size
- Storage bag and compression sack included
- 3 year manufacturer warranty
Updated 5 days ago · Based on the Amazon listing and published specifications, not hands-on testing.
A roomy down bag that zips down into a warmer mummy shape when nights turn cold. The temperature figure is listed two ways, so read the rating carefully.
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ASIN: B0DN3P4S4SModel: Boost 650Category: Sleeping Bags
Sizes Available
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Overview
Not a tight mummy bag, the Therm-a-Rest Boost is a semi-rectangular down bag with a center WarmZip that pulls the insulation close when you want more warmth. Arm holes let you reach out to read or cook without unzipping.
Adjustable shape is what sets it apart, giving side sleepers room on mild nights and a closer fit when it gets cold. Hydrophobic down and a recycled nylon shell help in damp weather, though down still needs care to stay dry.
Who it's for
Backpackers who toss and turn or sleep on their side will appreciate the extra width and the center zipper. Campers heading into hard freezes need a warmer bag.
Pros and cons
- WarmZip adds warmth on demand
- Wide cut for side sleepers
- Arm holes for use while inside
- Hydrophobic responsibly sourced down
- Temperature rating listed two ways
- Down still needs care when wet
- Fill weight not listed
Performance notes
Warmth depends on how much space the body has to heat: zipping the WarmZip pulls the down around the sleeper and shrinks that space. Zoned insulation puts more down on top and less underneath, where a pad does the work. A draft collar, draft tube and cinch hood stop heat leaking at the openings.
Specifications
| Brand | Therm-a-Rest |
|---|---|
| Model | Boost 650 |
| Dimensions & fit | |
| Maximum Height Recommendation | 6 feet |
| Size | Long Wide |
| Item weight | 2 lbs 14 oz |
| Item Dimensions L x W | 85 x 38.5 inches |
| Packed dimensions | 14.5 x 7.5 inches |
| Capacity & performance | |
| Temperature Rating | 32F/0C per title, minus 4 to 0 C per specs |
| Construction & materials | |
| Fill Material Type | 650 fill RDS-certified down |
| ShellMaterial | 100% recycled nylon, PFAS-free DWR |
| Color | Meadow Green |
| Included components | |
| Included Components | Sleeping bag, storage bag, compression sack |
| Warranty & support | |
| Warranty Description | 3 Year Manufacturer |
| Other details | |
| Occupancy | 1 person |
| Shape | Semi-rectangular |
| Closure Type | Center WarmZip plus two-way side zipper |
| Seasons | 3 seasons |
| Additional Features | Arm holes, draft collar, draft tube, cinchable hood |
Frequently asked questions
What comes with the Therm-a-Rest Boost 650?
The sleeping bag, a storage bag and a compression stuff sack.
Is the Therm-a-Rest Boost 650 a mummy bag?
No. It is semi-rectangular, but closing the WarmZip pulls it into a closer mummy like shape and can add up to 10F/6C of warmth.
What temperature is the Therm-a-Rest Boost 650 rated to?
The title says 32F/0C while the specs list minus 4 to 0 degrees Celsius. Plan around the warmer end of that range.
Does the Therm-a-Rest Boost 650 down handle damp weather?
The 650 fill down is hydrophobic and the shell has a PFAS-free DWR, both meant to help in wet conditions.