If you've spent one cold night in a hammock without insulation underneath you, you already know why this decision matters. The convection under an unprotected hammock strips heat fast — even air temps in the mid-50s F can leave your back numb by 3 AM. The fix is either an underquilt hanging below your hammock, or a sleeping pad inside it. Both work. But they work differently, and one of them is almost always the wrong answer for how you actually camp.
We build the Hawk Nest V.3, and we make both an inflatable Ultralight Sleeping Pad and the ThermoNest™ Premium Cold-Weather Underquilt. So we don't have a horse in the race — we sell whichever one fits your setup. This is our honest read on when each one wins.
The core problem: cold air moving under your back
Hammock camping cold isn't like tent camping cold. In a tent, the ground steals heat by conduction — direct contact between your body and the cold earth. A ground pad breaks that conduction path with foam or trapped air.
In a hammock, the ground is nowhere near you. The problem is convection: cool air flows freely under the fabric of the hammock, and your body weight compresses whatever's between you and that air stream. Down and synthetic fill from a sleeping bag underneath you gets crushed to almost nothing under your compressed weight. Compressed insulation = no insulation. The heat you're generating leaks out into the moving air below in every direction at once.
You'll see this called "cold butt syndrome" in every hammock forum on the internet. That's the phenomenon. Both an underquilt and a sleeping pad solve it — they just approach the physics from opposite sides.
What a sleeping pad does (and doesn't)
A sleeping pad goes inside the hammock, between you and the fabric. You lay on it. Your body compresses it, but a well-designed pad has enough baffled structure that even under compression it holds a barrier of trapped air (or closed-cell foam) between you and the hammock skin.
Our Ultralight Inflatable Sleeping Pad hits an R-value of 4 at 1.3 lb, uses 40D nylon with a TPU coating, and inflates via a stuff-sack pump so you're not blowing into it for ten minutes. R-4 is a real number — that's four-season territory for a pad, comparable to a NEMO Tensor Insulated or a Therm-a-Rest NeoAir XLite. In our V.3 the pad slides into a purpose-built stretch pocket underneath the hammock body, which stops the classic "pad slides out from under you at 2 AM" problem that plagued the V.1 and V.2.
What a pad gets you:
- Cost. Our Ultralight is $69.95 CAD. Any decent camping pad, hammock-specific or not, sits in that neighborhood.
- Cross-purpose use. The same pad works on the ground when the trees don't cooperate. If you switch between hammock and ground camping, a pad is dual-duty.
- Simplicity. No suspension system, no drop-length adjustment, no chin-strap fumbling in the dark. Roll it up, stuff it, go.
- Compact packed size. A 1.3-lb inflatable rolls to roughly the size of a coffee mug — smaller than any underquilt.
What a pad costs you:
- Comfort at the edges. A pad doesn't wrap you — it's flat under your back. Shoulder and hip pressure points aren't relieved by the hammock's natural curve because the pad is in the way. Diagonal lay helps, but a pad-only setup will always feel a bit flatter than a bare hammock or an underquilt setup.
- Movement. Even in our stretch pocket, aggressive side-sleepers can end up with a pad edge under their ribcage. Restless sleepers noticed this more.
- The moisture question. A pad on top of the hammock fabric traps humidity between you and it. Not a huge deal, but you'll notice it on a humid summer night.
- Rated to the pad, not the bag. An R-4 pad gets you comfortable sleep down to roughly -5 to -10°C / 15-20°F depending on the bag on top. Below that, a pad alone runs out of thermal budget fast.
What an underquilt does (and doesn't)
An underquilt hangs outside and underneath the hammock. It's not compressed by your body weight — you're on the other side of the hammock fabric. Instead, the quilt drapes below and around the curve of the hammock, held in place by suspension lines at the corners and (on ours) T-toggles that clip into loops under the support pole attachment points.
Our ThermoNest™ Premium Cold-Weather Underquilt is filled with 800g of 90% premium duck down, 700 fill power, in box baffles that keep the down evenly distributed. Total weight is 3 lb / 1.36 kg in an 82" x 50" cut. Comfort rating is -6°C to -17°C (20°F to 0°F), extreme is -25°C (-13°F). Shell is 400T nylon that packs to about 7" x 12" in the included compression sack. It's built for four-season use, and it's tested — one of our early-run customers took it out at -14°C and slept warm.
What an underquilt gets you:
- Real cold-weather range. At R-value equivalents around 6-8 (depending on how you measure down insulation against synthetic pad R-values), the ThermoNest is comfortable in temperatures that would put an R-4 pad in survival mode.
- True comfort. Nothing between you and the hammock — you get the natural, curved lay of the hammock itself. Diagonal-lay technique works exactly as intended.
- No shifting. Suspended below and around you, the underquilt can't slide out from under you the way a pad in an unsecured pocket can.
- Ventilation. Since the underquilt is outside the hammock, humidity from your body escapes down and out. No trapped moisture.
- Windproofing. In wind, an underquilt fights convection actively — the hood of down absorbs and traps the moving air layer against the hammock underside instead of stripping it.
What an underquilt costs you:
- Price. Our ThermoNest is $274.99 CAD. Down underquilts from the specialty brands sit in $250-450 territory. It's a real investment.
- Weight. 3 lb versus 1.3 lb for the pad. On a fastpacking trip or a thru-hike where every ounce matters, that's a real trade.
- Packed size. 7" x 12" compressed is bigger than a coffee-mug pad. Still fits in a 40L pack fine, but it's a chunkier piece of kit.
- Setup learning curve. Suspension length matters. A quilt hung too loose leaves gaps that convect heat. A quilt hung too tight creates flat spots that compress the down.
- No dual use. An underquilt does one thing — insulate below a hammock. It won't help you on the ground.
Weight, price, temperature: the real trade-off
Let's put the two side by side without marketing language.
| Metric | Ultralight Sleeping Pad | ThermoNest Underquilt |
|---|---|---|
| Weight | 1.3 lb / 0.6 kg | 3 lb / 1.36 kg |
| Packed | ~5" x 5" x 6" | 7" x 12" |
| Insulation type | R-4 inflatable | 800g 90% duck down, 700fp |
| Real-world comfort floor (with a 30°F bag) | ~15-20°F / -9 to -7°C | -17°C / 0°F |
| Extreme survival floor | ~5°F / -15°C | -25°C / -13°F |
| Price (CAD) | $69.95 | $274.99 |
| Works on the ground? | Yes | No |
| Slides during sleep? | Sometimes | No |
That table alone answers most people's decision.
If your camping stays above roughly 30°F / -1°C and you switch between hammock and ground use, a pad is almost always the right pick. If your camping regularly drops below 20°F / -7°C or you're building a dedicated cold-weather hammock system, the underquilt is the right pick and the price gap pays for itself in a single winter night that isn't miserable.
The tricky zone is the middle — the shoulder seasons, when you're camping in 15-35°F swings and don't want to carry both. That's where most people end up doubling up.
Can you use both? Yes, and here's when it makes sense
Layering a pad and an underquilt is a legitimate winter setup for temperatures below -15°C / 5°F. You get the underquilt handling the convection problem below and the pad adding an insulation layer that also blocks the small remaining conduction path where your body compresses the underquilt into the hammock fabric.
We know a few of our customers who run this stack for winter backcountry trips and it works. You'll pay for it in weight (4.3 lb of combined insulation before the sleeping bag) and packed volume. Not a fastpacking setup — this is base-camp or short-trip winter kit.
For summer? Doubling up is overkill. A pad or an underquilt alone will cover you.
The 60-second decision
Here's how we'd advise a customer walking into our shop.
Buy the sleeping pad if: - You camp above 30°F / -1°C the majority of the time - You switch between hammock and ground camping - You're a first-time hammock camper testing the system - Your total gear budget for the hammock system is under $500
Buy the underquilt if: - You camp regularly below 30°F / -1°C - You're a dedicated hammock camper who doesn't ground-camp - You've had a cold night in a hammock and want it to never happen again - You want the most comfortable lay possible (nothing between you and the hammock)
Buy both if: - You want a serious four-season hammock system - You're building for below -10°C / 15°F camping - You're doing multi-day winter trips where recovery matters more than pack weight
For further reading on how the underquilt actually attaches and behaves through a full season, we wrote a full breakdown on the hammock tent underquilt. And for the broader insulation strategy across three seasons, our full hammock tent insulation techniques piece covers wind blocks, top quilts, and vestibule use.
What we recommend in the Hawk Nest kit
The V.3 was designed around insulation flexibility. The internal stretch pocket accepts pads up to 28" wide and 3" thick — that fits our Ultralight, the NEMO Tensor, and the Therm-a-Rest NeoAir line without issue. The T-toggle underquilt attachment loops are underneath the pole attachment points, engineered specifically to fit our ThermoNest but universal enough for third-party underquilts.
If you're building a shoulder-season kit and want to keep it lean, our combination is: V.3 + Ultralight Pad + a 20°F sleeping bag. That's a 3-season setup under $500 CAD that handles 20°F comfortably.
If you're building for winter or you want to future-proof, the V.3 + ThermoNest + a 20°F bag setup will run you into the mid $700s CAD and give you real -15°C / 5°F sleeping comfort. For a full breakdown of what changes when you push into deep-winter territory, we wrote up the whole cold-weather hammock system here.
The one thing everyone gets wrong
The mistake we see over and over from first-time hammock campers: pairing a summer-weight sleeping bag with no bottom insulation, and thinking the bag will handle it. It won't. The bag underneath you compresses to nothing under body weight — you'll sleep colder in an unprotected hammock at 50°F than you would in a tent with the same bag at 40°F.
Either add a pad, add an underquilt, or don't hammock in temps below about 65°F / 18°C. The V.3 sells against tents on comfort and versatility, but it's an honest system — it needs bottom insulation to work below room temperature. Nobody's hammock skips that requirement.
Ready to build your system?
If you're new to hammock camping and want the simplest, cheapest way in that still handles temperatures down to freezing, start with our Ultralight Sleeping Pad plus the V.3 pre-order. It's the setup we recommend for 80% of first-time hammock buyers.
If you already know you're a cold-weather camper — hunters, winter backpackers, alpine trip planners — go straight to the ThermoNest Underquilt. You'll never wish you had the pad instead.
Either way, both are compatible with the V.3 pre-order and both drop-ship in the same shipment when your batch runs. Questions on which is right for the specific trip you're planning? Email us at support@hawknesthammocks.ca with the temperature range you're expecting and we'll spec the kit for you.