What provides more warmth TQ or UQ ?

[Can't Wait]

I was wondering I am going to be ordering a down incubator which with 900 fill will make a - 5 ° UQ now I can't afford to buy a burrow this season but will be using my montbell 650 fill 20 ° bag as a top quilt, would you think I can get to single digits with the the added warmth from the bottom, I eventually want to get a 0 ° TQ whats people thoughts thanks

[Sarae]

I'm curious about this, too. Looking forward to the opinions!

[angrysparrow]

Having the warmer quilt underneath you will definitely help. But extending a 20ºF bag to 0ºF may require you to add more puffy clothing, or a liner of some sort. Perhaps a fleece bag liner would help.

Be sure to cover your head with a hood if not using the bag mummy-style. That makes a big difference.

[Trooper]

I'm convinced a UQ is more important, and the warmer the UQ, the less top insulation you will need. You will of course need insulation on top, just not as much if you have a very warm UQ.

It is hard to say if a 20°F bag will get your to single digit temps, but I would say it is possible but pushing it.

[GrizzlyAdams]

I'd go for the heavy stuff below, and then add layers on top. In the winter I wear insulated clothing to bed and can get by with less on top because of that. YMMV

[dejoha]

I'm convinced a UQ is more important, and the warmer the UQ, the less top insulation you will need. You will of course need insulation on top, just not as much if you have a very warm UQ.

I'll give a +1 to this.

In my experience, a 0°F rated top quilt will feel like a 60°F quilt with a poor UQ. Not sure that made sense. Put another way, when my backside is freezing, there isn't much I can do on top to compensate.

I think this is true of ground sleeping as well. Last weekend I had to sleep on the ground and had my very warm top quilt but a sub standard ultralight torso pad and I nearly froze a few times. Hot on top, cold on bottom -- made me feel cold in the middle too.

[Can't Wait]

I don't sleep inside like a bag it's my TQ until I can afford one was figuring on wearing poly long johns balaclava warm hat and wool socks maybe a fleece top.

[jloden]

I have minimal experience here as I'm still new to this, but based on my experiences so far I would echo what angrysparrow said. The UQ is most important because you're losing so much heat from below in a hammock. You're likely to have cold air moving across your backside which robs heat faster than what you'd lose through the TQ, where you're protected with the tarp.

The sleeping bag may be tricky, their ratings are usually "keeps you alive at X temp" versus "toast down to X temp" like most quilt ratings. You'd really need to do some backyard testing to see what your comfort limits are. If you can't afford a new TQ there are plenty of other options to get yourself down to single digits. A poncho liner or extra blanket added to your TQ, extra clothing, or hot water bottle all come to mind. You could also try an overcover or hammock sock, that has been known to add something like 10° of warmth.

[JohnSawyer]

Agreed. I've slept COLD at 40 with a 20-degree down mummy as a top quilt, because my UQ wasn't properly adjusted...

Cold Butt Syndrome sucks

[MacEntyre]

I think the UQ needs to be more insulation than the TQ.

However, if you don't have enough on top, it can make it feel like you don't have enough below. It's an interesting psychological phenomenon.