Thermarest Vesper 20F Quilt – Super Lightweight Sleeping System

Kyle Juszczyk

 

The Thermarest Vesper 20F Quilt was designed for gram-shaving and space-limited adventures in the mountains. I picked one up for spring ski mountaineering and summer alpine climbing, where pack size and weight can make or break a trip. It clocks in at 19oz (550g) and is insulated with 900 fill down, allowing it to compress unbelievably small.

By choosing to pick up a Vesper 20F, I was not only testing out this specific quilt but having never used any quilt, I was also testing out this style of sleep system. I’ve been super pleased with the quilt so far, and I am likely moving away from using full sleeping bags in the spring and summer. Unfortunately, spring skiing season closed out early, so I wasn’t able to give this thing a true test of it’s low-temperature performance. 

Thermarest Vesper 20F Quilt review

Temp Rating

With a 20F rating, I was hesitant to bring this quilt along for a few trips this past week in August on Baker and Shuksan. Though I purchased this quilt with summer trips in mind, using it with nighttime lows of 50F was not within my intent. In the end, the quilt was smaller and lighter than my 30F bag, so I went for it. I was pleasantly surprised with how it handled warmer temps. Because it’s more like a blanket, users have more blanket-style options to titrate their warmth. As I mentioned earlier, I have not been able to use this bag close to the 20F rating. I will be sure to update you when I have the chance.

Quilts are pretty cool

I’m sold on the quilt-style sleeping system for 3 season adventures. I was initially hesitant, as I was certain that I’d hate sleeping directly on a pad. I assumed I’d stick to it and get all sweaty, or I wouldn’t be able to get the quilt to seal to the pad, or that my pillow would run away from me all night because I couldn’t stuff it in the hood of the bag. I ended up being wrong on all accounts and even found that there were benefits to the quilt that I didn’t anticipate.

Most can be summarized by the idea that the quilt works more like a blanket/comforter that I’m used to using on a real bed. You can roll around without having to keep the bottom on the bottom, and you can pull it down evenly across your torso without exposing one entire side of your body to a cold draft. That’s all good and well, but the point that sealed the deal is that because the quilt naturally has an opening above the foot box, you can stick one leg out from underneath the quilt, allowing for absolutely perfect temperature regulation (see diagram below.) 

Weight and size

The weight of the bag is pretty exceptional compared to other 20F full sleeping bags. For example, it’s about 250g lighter than Therm-a-rest’s own Parsec ultralight 20F bag. It’s even 131g lighter than my Mountain Hardwear’s Phantom 30F bag.

Though the weight savings are significant, the truly exceptional quality of this quilt is its compressibility. The three things that I believe contribute to its amazingly small size are the missing material that makes it a quilt, the 900 fill down, and a compression sac that’s actually small enough.

I imagine I’m just late to the party with quilt adoption, but it makes a ton of sense for 3 season use. Furthermore, with how insulated pads are getting these days, it’s become a no-brainer to cut out the extra material from a sleeping bag. 900 fill down feels like the amps that go to “11” from Spinal Tap. I’m sure 850 fill is fine, but why not just get the down fill that “goes to 11.”

It’s a funny thing to be so stoked about, but the compression sac that comes with this quilt makes me so happy. I usually have to stuff another puffy in with my bag to feel like I’m getting my money’s worth out of the space savings. I tried that with this bag, and for the first time, I maxed out a manufacturer-specific compression sac. Therm-a-rest claims that the Nikwax treated down maintains loft 60 times longer than untreated down, so I’d bet that has something to do with them providing a legit compression sac.

Features

Therm-a-rest describes this quilt as “no-frills,” and I’d agree that there are no earth-shattering bells and whistles on it. However, there are a few notable features that facilitate solid function. Possibly most important are the SynergyLink Connectors.

I personally would have picked a more modest name, but maybe that’s why I’m not in marketing. These are the straps that keep the quilt secured to your sleeping pad. They’re removable and function with a pad up to 3” thick. I found they do an excellent job and paired well with my Therm-a-rest NeoAir XTherm NXT pad.

One night did get chilly enough for me to try out the “snap neck closure.” Again, I’m not a marketing person, but the thought of a snapped neck is something I try to avoid. Anyway, they’ve placed snaps at both sides of the top of the quilt so that you can put the snaps together behind your head and create a neck baffle, similar to a standard sleeping bag.

I was most surprised at how well the perimeter side baffles were sealed against the pad and kept drafts out. In general, the quilt sealed effortlessly to my pad despite rolling around a ton. 

Conclusion

I couldn’t be happier with the Therm-a-rest Vesper 20F Quilt. The basic, effective design simply delivers warm, comfortable sleep that disappears into a tiny compression sac. I think anyone who’s looking for a lightweight sleep system for spring or snowy summer adventures should check out this quilt. It pairs perfectly with a Therm-a-rest Xtherm pad for a completely insulated sleep system. 

 

Kyle Juszczyk

Kyle grew up in Iowa and after high school ditched the midwest to begin college at Western State Colorado University and start guiding in the summers. 

Kyle says he spent his time at Western climbing, snowboarding, volunteering on the rescue team, and instructing for the outdoor program. He claims if he had spent any less time actually in class he certainly would not have graduated. Kyle’s time with the Western Mountain Rescue Team was extremely formative and revealed his passion for wilderness search and rescue (SAR). He made it his goal to make a career out of SAR. Kyle is well on his way to achieving his goal and currently works as a Ski Patroller in Colorado and a Climbing Ranger in the Pacific NorthWest.

Kyle’s certifications include WEMT-IV, Avalanche Pro 1, and AMGA Single Pitch Instructor. Kyle is a certified AIARE instructor and teaches Recreational Level 1, Level 2, and Partner Rescue courses. He is also an Apprentice Rock and Ski Guide through the AMGA

 

When Kyle has free time he climbs and skis. He’s taken the hard way to the top of El Capitan and the steep way down peaks in Colorado and Washington.

Kyle’s jobs allow or force him (depending on the weather) to work 200 days a year outside. He’s constantly testing gear in all conditions and refining his setups to make work and play easier, faster, and more fun.