Boost 650™ 32F/0C Sleeping Bag

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Therm-a-Rest

Boost 650™ 32F/0C Sleeping Bag

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Exclusively at REI through December 31st

Ultra-comfy three-season backpacking sleeping bag with adjustable shape and warmth.

  • Customizable Comfort: Enjoy the spacious freedom of the semi-rectangular bag or the cozy warmth of a mummy bag—pick the shape and temperature that keeps you comfy at night with just a zip.
  • WarmZip™ Tech: Patent-pending center zipper design zips up to reduce the bag’s internal space and tuck insulation around the sleeper to boost warmth by up to 10F/6C.
  • Multi-Use Arm Holes: Reach the WarmZip, read a book, play cards or simply ventilate—do it all while tucked into your sleeping bag for elevated livability.
  • Plush & Puffy: 650-fill RDS-certified hydrophobic down is allocated to key areas with Zoned Insulation for refined heat efficiency and maximum coziness.
  • Eco-Conscious Materials: Shell and liner are made of GRS-certified 100% recycled, soft-to-the-touch nylon and coated with PFAS-free water repellent.
  • Inclusive Sizing: Each size—Small, Regular, Long—is also available in a Wide size, so you get the bag you want in the fit you need.
  • Additional Features: YKK anti-snag zippers, cinchable hood, zipper draft tube, puffed draft collar, and a two-way entry zipper.
  • What's Included:
  • ✓ Compression Sack

    ✓ Storage Sack

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From backpacking trips to car camping excursions, the Boost 650 provides the dreamy comfort you need to sleep well outdoors. With an innovative design that allows you to adjust its shape and add warmth when needed, the Boost is one of the most comfortable and versatile sleeping bags ever made. The semi-rectangular shape gives you considerably more internal space than a mummy bag—you’ll feel unrestricted and free to sleep in whatever position you want all night long. But more space demands more body heat to warm it up and cold isn’t comfortable. That’s where WarmZip comes in. Zipping up the WarmZip center zipper transforms the shape of the Boost 650 from a semi-rectangular bag to a thermally efficient mummy bag. It pulls the 650-fill down around your body and reduces the amount of space your body needs to heat. WarmZip gives you the power to add up to 10F/6C to the Boost’s temperature rating. Standard Therm-a-Rest features like a puffy draft collar, a draft tube along the entry zipper line and a cinchable hood round out the Boost’s bliss-inducing comfort.

We designed the Boost 650 to be comfortable when you’re falling asleep, when you’re asleep and when you’re wide awake and hanging out in your tent. The arm holes give you easy access to the WarmZip without having to use the side zipper. They also allow you to access your belongings, read a book, play cards or high-five your friends without leaving the cozy warmth of your sleeping bag. Getting too warm? Use the arm holes to ventilate or comfortably sleep with just your arms out. You can also ventilate around your torso or down by your feet with the two-way side zipper. Every zipper line on the Boost has a durable YKK anti-snag pull to eliminate annoying snags and damaging tears.

All that comfort must be bulky and heavy, right? Think again. The Boost 650 was built to backpack—we dialed in the materials and design to make it light, packable and high-performing in variable backcountry conditions. Zoned Insulation places the 650-fill hydrophobic down in key warmth-retention areas (on top, around your core and shoulders) and reduces it where it’s less efficient (on the bottom), allowing the Boost to create more warmth with less down. The shell and liner are made of 100%-recycled nylon that was handpicked for its light weight and super-soft feel. The PFAS-free DWR coating and the hydrophobic down keep the Boost warm and comfy even in wet weather.

Short Short Wide Long Long Wide Regular Regular Wide
SKU 14195 14196 14199 14200 14197 14198
Color Meadow Green Meadow Green Meadow Green Meadow Green Meadow Green Meadow Green
Weight (Standard) 1 lb 12 oz 2 lb 2 oz 2 lb 7 oz 2 lb 14 oz 2 lb 2 oz 2 lb 8 oz
Weight (Metric) 0.80 kg 0.95 kg 1.10 kg 1.32 kg 0.95 kg 1.12 kg
Length (Standard) 73 in 73 in 85 in 85 in 80 in 80 in
Length (Metric) 188 cm 188 cm 216 cm 216 cm 203 cm 203 cm
Fits (Standard) 66 in 66 in 78 in 78 in 72 in 72 in
Fits (Metric) 168 cm 168 cm 198 cm 198 cm 183 cm 183 cm
Girth Shoulder (Standard) 63 in 75 in 65 in 77 in 64 in 76 in
Girth Shoulder (Metric) 160 cm 191 cm 165 cm 196 cm 163 cm 193 cm
Girth Hip (Standard) 59 in 73 in 61 in 75 in 60 in 74 in
Girth Hip (Metric) 150 cm 185 cm 155 cm 191 cm 152 cm 188 cm
Girth Foot box (Standard) 61 in 61 in 61 in 61 in 61 in 61 in
Girth Foot box (Metric) 155 cm 155 cm 155 cm 155 cm 155 cm 155 cm
Packed dimension (Standard) 8in x 6.5in 10in x 6.5in 11in x 6.5in 12in x 7.5in 10in x 6.5in 11in x 6.5in
Packed dimension (Metric) 20cm x 17cm 25cm x 17cm 28cm x 17cm 30cm x 19cm 25cm x 17cm 28cm x 17cm
EN Comfort (C) 5 C 5 C 5 C 5 C 5 C 5 C
EN Comfort (F) 41 F 41 F 41 F 41 F 41 F 41 F
EN Limit (C) 0 C 0 C 0 C 0 C 0 C 0 C
EN Limit (F) 32 F 32 F 32 F 32 F 32 F 32 F
EN Extreme (F) 5 F 5 F 5 F 5 F 5 F 5 F
EN Extreme (C) -15 C -15 C -15 C -15 C -15 C -15 C
Fill material 650 Fill Duck PFAS Free Hydrophobic Down, RDS 650 Fill Duck PFAS Free Hydrophobic Down, RDS 650 Fill Duck PFAS Free Hydrophobic Down, RDS 650 Fill Duck PFAS Free Hydrophobic Down, RDS 650 Fill Duck PFAS Free Hydrophobic Down, RDS 650 Fill Duck PFAS Free Hydrophobic Down, RDS
Fill weight (Standard) 12 oz 1 lb 1 lb 1 lb 5 oz 14 oz 1 lb 3 oz
Fill weight (Metric) 0.35 kg 0.47 kg 0.45 kg 0.61 kg 0.40 kg 0.54 kg
Shell fabric 20D 100% Recycled Nylon Rip Stop 20D 100% Recycled Nylon Rip Stop 20D 100% Recycled Nylon Rip Stop 20D 100% Recycled Nylon Rip Stop 20D 100% Recycled Nylon Rip Stop 20D 100% Recycled Nylon Rip Stop
Lining fabric 20D 100% Recycled Nylon Rip Stop 20D 100% Recycled Nylon Rip Stop 20D 100% Recycled Nylon Rip Stop 20D 100% Recycled Nylon Rip Stop 20D 100% Recycled Nylon Rip Stop 20D 100% Recycled Nylon Rip Stop
Zipper side Left Left Left Left Left Left

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What is the Better Sleep Guarantee?

All Therm-a-Rest sleeping bags and quilts are also covered by our Better Sleep Guarantee. When you wake up on a Therm-a-Rest sleeping bag or quilt, we're confident you'll wake up feeling better than ever. If you are not completely satisfied, return it within three months with the original receipt of purchase and we will give you a full refund- no questions asked.

Why are Therm-a-Rest® sleeping bags so great for side sleepers?

Therm-a-Rest® sleeping bags are designed to accommodate a wide range of sleep positions. Therm-a-Rest sleeping bags are designed with extra room in the torso to allow your shoulders, elbows and hips to move freely. At the head and foot the fit is closer, keeping you warm and decreasing overall weight. In addition, the placement of our SynergyLink connectors is optimized to keep the mattress secure while you roll, yet allow the head and foot of the bag to rotate 90-degrees in either direction, following you for maximum comfort and warmth.

What is eraLoft synthetic insulation?

Therm-a-Rest® sleeping bags use a unique synthetic insulation that incorporates the best characteristics of both short and long staple insulation. Our EraLoft™ synthetic insulation uses three distinct fibers to create a structure that is lightweight, compressible, warm and durable. The hollow fibers are highly resistant to water and provide warmth even when wet. The insulation is built into Therm-a-Rest® sleeping bags using shingle construction, a configuration that minimizes heat loss and provides the most efficient performance.

How warm is my sleeping bag and what is the EN/ISO Standard?

The new ISO standard has made a few updates to the previous EN rating system. All Therm-a-Rest sleeping bags have been adhering to the most updated standards and tested in our on-site cold chamber. For more info on the EN/ISO testing, head over to our blog.

Is your down ethically sourced?

Therm-a-Rest actively supports industry-wide efforts to ensure all down-filled products are made with the least harm possible. We are opposed to inhumane practices and actively work with peers across all industries to improve the treatment of geese. Our product development team plays an active role in the Outdoor Industry Association (OIA) and its Textile Exchange Materials Traceability Working Group (TEMTWG). Our team also serves on the TEMTWG Down Task Force, working to address key issues in the down and feather industry and manufacturing supply chain.

To learn more about OIA Working Groups visit: www.outdoorindustry.org/resources.working

How should I store my sleeping bag?

Sleeping bags should be stored dry and loose (not compressed) in order to extend the life of the bag. All Therm-a-Rest® sleeping bags come with a storage sack well suited for long term storage. For short-term storage or when shipping, use the compression sack to save space.

How do I clean my Therm-a-Rest® sleeping bag?

Follow the care instructions below to help maintain the high quality and extend the life of your down or synthetic Therm-a-Rest® sleeping bag.

 

Hydrophobic Down Care Instructions:

All hydrophobic down treatments wash out over time, and washing is hard on all down. Extend the life of your bag by spot cleaning with a damp sponge, and only machine washing when necessary.

Washing

Hand wash or machine wash in a large capacity, front loading washing machine, using 3 oz. of Nikwax® Down Wash™. Select cold water and a gentle/delicate cycle with two rinses. We recommend an additional spin cycle as well to extract as much water as possible before drying.

DO NOT dry clean. DO NOT bleach. DO NOT iron.

Drying

Hang dry your bag whenever possible. This can be a long process (24-48 hours or more), but this is by far the best way to get the longest life from your down. Use a well-ventilated, low-humidity environment. Hand-tease or shake out your bag gently to break-up down clumps, and flip it often to help speed the process.

If you need to dry your bag faster, tumble dry in a large dryer on low heat. As your bag gets drier, it will begin to loft and can actually fill the dryer chamber, preventing it from tumbling. This can cause hot spots and even melt the bag's shell, so check it often for overheating and visually inspect frequently to make sure it's tumbling. When you check it, feel for clumps of wet down and either shake the bag gently or hand-tease the clumps apart to redistribute down. Throwing in 3-5 tennis balls can help agitate the bag, breaking up those wet down clusters to speed dry times.

 

Nikwax® Hydrophobic Down Treatment and Re-Treatment

Use Nikwax® Down Proof to restore your down's hydrophobic properties. Specially formulated to renew the Nikwax Hydrophobic Down treatment, it can also be used to provide improved water-resistance to any down bag. Follow directions on the bottle.

Storage

The less time your sleeping bag is compressed, the longer it will serve you by maintaining the loft necessary to keep you warm. Store your sleeping bag loose, in a cool, dry place. If you must store it in a bag, use the extended storage sack it came in, or something even larger. Never use a waterproof bag for long-term storage.

 

Eraloft Insulation Care Instructions:

Washing

Hand wash or machine wash in large-capacity, front loading washing machine. Use a mild, non-detergent soap. Select cold water and a gentle cycle with two rinses.

DO NOT dry clean. DO NOT bleach. DO NOT iron.

Drying

Hang dry your bag whenever possible. This can be a long process (24-48 hours), but this is by far the best way to get the longest life from your bag. Use a well-ventilated, low-humidity environment. Unzip fully and flip it often to help speed the process.

If you need to dry your bag faster, tumble dry in a large dryer on low heat. As your bag gets drier, it will begin to loft and can actually fill the dryer chamber, preventing it from tumbling. This can cause hot spots and even melt the bag's shell, so check it often for overheating and visually inspect frequently to make sure it's tumbling.

Storage

The less time your sleeping bag is compressed, the longer it will serve you by maintaining the loft necessary to keep you warm. Store your sleeping bag loose, in a cool, dry place. If you must store it in a bag, use the extended storage sack it came in, or something even larger. Never use a waterproof bag for long-term storage.

Are Therm-a-Rest sleeping bags under warranty?

Therm-a-Rest® offers a Limited Lifetime Warranty for most products including all sleeping bags. Your sleeping bag is guaranteed without time limit against defects in materials and workmanship. We also offer repair services for damages not covered under warranty. Learn more about Therm-a-Rest® Warranty & Repair.

Why were ThermaCapture Linings removed from Therm-a-Rest sleeping bags?

For environmental and manufacturing reasons, we decided to remove the ThermaCapture linings from our sleeping bags. After reviewing the cost-benefit of putting the material in our bags, we could no longer justify the environmental and logistics cost. The sleeping bag specifications will see minimal changes if any and the bags will remain under the Better Sleep Guarantee.

Why should I consider using a Therm-a-Rest quilt?

Using a quilt can save you weight, allow for multiple sleep positions and versatility to your sleep system. To learn more by checking out our blogs on Backpacking With A Quilt and Understanding The Underestimated Camp Quilt.

How does WarmZip™ add warmth?

WarmZip converts the sleeping bag into a more thermally efficient mummy shape, decreasing dead air inside the bag and holding the bag’s insulation closer to your body. A key WarmZip effect is pulling the insulation of a wider semi-rectangular bag into a narrower space, resulting in a thicker, and therefore warmer, layer of insulation on top of the body. For an in-depth look at the WarmZip effect, check out this blog article: https://www.thermarest.com/blog/warmzip-sleeping-bag-temperature-ratings

Does the Boost 650 have two EN/ISO temperature ratings?

No. The Boost 650 has one EN/ISO temperature rating, and it rates the Boost in its default, semi-rectangular shape. We exhaustively tested WarmZip and can confidently say that it adds warmth, but the data collected from those tests cannot be used to determine an EN/ISO temperature rating. For a more detailed explanation, check out this blog article: https://www.thermarest.com/blog/warmzip-sleeping-bag-temperature-ratings .

What does WarmZip do?

When WarmZip is open (zipped down), the bag is a spacious, semi-rectangular shape. When it’s closed (zipped up), the bag converts to a mummy shape. Closing WarmZip adds up to 10°F/6°C of warmth to the sleeping bag.

What is WarmZip™?

WarmZip is a sleeping bag design innovation found on the Boost 650 that empowers you to customize the shape and warmth of your bag. It’s a zipper that runs on the top of the sleeping bag, up the center from footbox to chest.
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Orders Shipped in 1-2 Days

We do our best to get all orders out within one business day, Monday through Friday. Learn More

No Hassle Returns

We accept returns within 30 days of purchase. All returned items must be in new condition. Please be sure no dirt, grass or pet hair is on the item you are returning. Learn More

Limited Lifetime Warranty

Every piece of Therm-a-Rest gear is designed to endure the rigors of your time in the backcountry. We offer a Limited Lifetime Warranty on all products, except electronic devices, which have a 2-year Limited Warranty. Visit our Therm-a-Rest warranty page for more info.

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  • WarmZip™

    Patent-pending center zipper allows you to choose a semi-rectangular or mummy shape, or somewhere in between. Boosts the bags warmth by up to 10F/6C when zipped up in the mummy shape.
  • Arm Holes

    Access the WarmZip, ventilate, read a book, play cards or high five your friends—all without leaving the warmth of your sleeping bag. Arm holes make being in your bag and living in a tent comfy and easy.
  • Humanely Sourced Down Insulation

    650-fill hydrophobic down is certified to be sourced from humanely treated waterfowl by the Responsible Down Standard (RDS).
  • 100% Recycled Nylon

    Shell and liner are certified 100% recycled by the Global Recycle Standard. Recycled nylon is made of plastic bottles and reduces water and energy waste in the textile supply chain.