View Full Version : Staying Warm?+ Hennessy hammock

2004-11-24, 22:58
It looks like that no-one reads the staying warm hammock board. I looked over it, and read threads for about an hour. I am very confused.

A little background about myself. I am getting a Hennessy hammock for Christmas, and I plan to use it on a January trip, it will most likely get down to low 30's, maybe upper 20's. I read all those posts and was confused. I do not want to sew anythign for my first trip, I am very very poor at sewing. What else can be done to improve the warmth. My usual camping set up is a guidlelight therm-a-rest- my lafum 35 degree bag, and a liner. I was thinking for this trip to bring my Lafuma 60 degree summer bag, as it almost weighs as much as the liner.

Can some please explain all about the keeping warm and the differnt options. I read about the under-quilts but they seemed like alot of work for 1 cold weather trip a year. In Georgia, it does not very cold except for Jan and Feb.

Also, I have been reading about the rain-fly. When it is raining is it large enough to cook under. I know that you can rig it to provide protection from the wind and such.

I have seen people use a small peice of Tyvek under the hennesy hammock to serve as a little "door step" a place to sit on and place your boots on etc. Would you guys reccomend this? Also can you go buy a 2x2 peice of Tyvek at your local home depot or do you have to go elsewhere.

I am so excited about getting my Hennessy.


2004-11-25, 09:00

I've done a little backpacking with a hammock in north Georgia in winter months. What area are you looking at where you are expecting low 30's, maybe upper 20's in January?


2004-11-25, 10:57
...Can some please explain all about the keeping warm and the differnt options. I read about the under-quilts but they seemed like alot of work for 1 cold weather trip a year. In Georgia, it does not very cold except for Jan and Feb.

Also, I have been reading about the rain-fly. When it is raining is it large enough to cook under. I know that you can rig it to provide protection from the wind and such....

That is a tall order and I don't think I can anwser all of it, certainly not in this post.

Staying warm in a hammock is fundamentally different than staying warm when sleeping on the ground because on the ground, you can use your body heat to warm the ground that you are laying on and the slightest wind (forced convection) or natural convection (warm air rises and is replaced by cooler air) currents will not rob you of this boundry of warmness. The biggest difficultly is staying warm on the bottom of the hammock. (On the top side, things work pretty much the same as for ground dwellers.)

At the same outside temperatures, you need more insulation beneath you in a hammock than you would if you were sleeping on the ground. If your guidelight mat was marginally warm enough on the ground, you would need to augment it with something to make it warm enough in the hammock. Width and length of the bottom side insulation is also different in a hammock... you need more of both because of the curves involved and because the hammock tends to partially wrap around you. On the ground you might slightly hang off the edges of your mat and your sleeping bag would loft to fill in that area, but in a hammock the wrapping tends to compress that insulation and render it less effective... this is usually noticed most in the shoulder area.

Well, that is start at defining the unique problem and I need to get ready for T-day... so have a good one yourself and we can take this up later. I suspect others will have somethings to say about all this as well.

BTW, in what area of Georgia do you live?


Hog On Ice
2004-11-25, 11:55
With respect to keeping warm in a HH - my experience is that for 20-30 deg F weather that the Guidelite Thermarest is not sufficient to keep you warm (I once froze my ass off trying to use a Guidelite in the cold) - the Thermarest LE comes closer but still questionable below freezing in my opinion. What I use these days is a down filled air mattress (DAM) - in particular I use an Exped 20 by 72 by 2.5 inch - so far I have keep warm in the hammock with the DAM. Downside to using the DAM in the HH is the volume that it occupies - for me this is not an issue since I use one of the larger HHs - an Explorer Deluxe A-Sym - even here however it is noticeable how much closer I am to the mesh. Another possible issue with the DAM is if it blocks the slit in the bottom - if so it is a gold plated bitch to get back out of the hammock once you have gotten in and on top of the DAM - imagine trying to fold the end an air mattress with your feet while laying on it (max pressure). Fortunately for me this is not an issue - the HH Explorer A-Sym is large enough to roll off the DAM and then get out of the slit.

Another possible and cheaper approach is to use two or even three of the blue closed cell foam pads strapped together - very bulky to carry but fairly light and the 1.5 inch thickness will also keep you warm - round the corners and trim the foot end some and it should fit well into the hammock.

Another way to go is to use the blue foam pad plus your Guidelite pad strapped together.

One important thing to note - if you are not using full length pads then your feet will get cold - put something under your feet - possibly your pack or some extra clothing that you are not sleeping in. To keep your shoulders warm put some extra clothing around your shoulders - I use the heavy weight polypro army longjohns - top for one side and bottoms for the other.

As for the sleeping bag its as Youngblood says - if it will keep you warm on the ground it will keep you warm on top of you in the hammock - I usually use a somewhat lower temp rated bag (0 deg F) but that is only because I don't have a 20 deg F bag. I think from your description of double bagging a 35 deg and a summer bag that you may be OK but it is difficult for me to say not having used that combination before. Note on using a bag in a hammock - I only zip it up to about knee level and then I use the bag as a quilt - it is a whole lot of working getting into a bag the "right" way in a hammock - much easier to use it as a quilt and just tuck it around you while you are laying on your pad.

2004-11-25, 20:31
Thanks for the replies

Youngblood, We did Rabun Bald 2 years ago, got snowed on. Prolly one of my fav trip I have ever done on. If you go far enough north and pick it out. If you hit the AT, In jan you can get snowed on and get to 20. Blood Mt. has snow on it sometimes. I live around Atlanta

I am getting the expedition Asym, I am gonna go toy around in my other hammock tonight. I have been looking, at the garlington insulator, is that an easy thing to make a for a person with little sewing experince?

Also, is the rain fly on the Expedition Asym large enough, I have seen that they have a double Hex. I want to be able to sit under there and cook if it is raining, but not anything too large.


2004-11-25, 22:28
Check the articles on www.jacksrbetter.com (http://www.jacksrbetter.com) " So you want to be Warm" and "Nesting Tricks of an Old Coot" offer a lot in the subject of comfort whatever the temperature.

2004-11-26, 09:33

2004-11-26, 10:50
Sounds Intresting, I will look at it more throughly when I get back.

I slept in my small nylonish hammock last night, I was super warm till I took out my Therm-a-rest pad, but the hammock was too small for the pad and me, but the hammock is perfect for summer. so About 2 hours after taking out the pad, I came back inside.

Can;t wait till I get my HH

2004-11-26, 13:48
Tyvek? you can only buy in large rolls... unless you buy it here (http://www.geocities.com/amytys/Tyvek.htm), here (http://www.trailquest.net/dlgctyvek.html) or damn, looks like the hang-em-high site is down

oh, and btw - don't buy any FUD you read on the internet about reflective insulation being better for the underside (radiant heat loss is directly related to the SURFACE temperature between the two objects that are at a distance, the outer surface temperature of the insulation will always be low enough that radiant heat loss is not a factor), the key is creating dead air spaces with no windpermeability, this can be accomplished by a underquilt (with a windproof outer layer) or closed cell foam

2004-11-26, 14:30
I was reading about the Garlington thing, and how they placed insulation such as air filled trash bags and such inbetween, would that work, I am not up for making or buying an underquilt at this time,

what would I use to make the Garlington.

I will talk to one of my contractor friends and see if he can round me up some tyvek scraps

2004-11-27, 00:20
Intresting thing. I was sitting here reading a thread about a bivy, and I was like I can do that. I took a sleeping bag, ran the rope thru the bottom zipper thingie, and zipped it back up. Laid down and was toasty, wanted to cover my head area, got a light sleeping bag put that around the other way. Laid in there for about 20 minutes was mighty warm, will be an improvment of last night's expermint.

I am just using a just a nylon parchute hammock atm, HH won't be getting till christmas, http://www.rei.com/online/store/ProductDisplay?storeId=8000&catalogId=40000008000&productId=47605147&parent_category_rn=4500553&vcat=REI_SEARCH

Last night, i hung my hammock, used a therm a rest, laid my sleeping bag on top, was warm for an hour, but couldn;t fall asleep becuase the hammock wasn't wide and long enough to accomdate hammock. Threw the pad on the ground, zipped up bag, got cold, stayed out for an hour, then finally came back in


2004-11-27, 12:04

2004-11-28, 02:42
Sounds intresting, so last night, I was bored, i took 2 sleeping bags, and zipped them around the hammock. One went to about my neck, and then I put the other one higher up. I was very warm, but I had a hard time getting comfortable, hammock is too small to really get comforable in. I also, took a warm water bottle with me, I really liked that.

I fell asleep, woke up an hour later, my upper back was cold, becuase my upper sleeping bag had lost contact with the bottom of the hammock. I fixed it, and was warm again, but couldn't get comfortable, came inside and slept on the couch.

How hard is Silionylon to sew? I mean like slippery wise and such, some fabrics are very slippery and therefore hard to sew with a machine

2004-11-28, 08:54
...How hard is Silionylon to sew? I mean like slippery wise and such, some fabrics are very slippery and therefore hard to sew with a machine

It is very slippery and can be frustrating to work with, tape won't quite stick to it. Of course, big pieces of fabric compound these difficulties.

2004-12-01, 10:26
Very good point, I've noticed that when I camp with the boy scouts, my but gets cold when I"m lying on top of my sleeping pad on the ground... my solution? I started putting the fleece jacket I always take under my but rather than just in the bag with me (to keep it warm for the morning), now my butt is toasty along with the rest of me... :biggrin:


I am going to mention this before I forget. When you do cold weather experiments, it is helpful to try an determine exactly where you are cold at. With that information sometimes you can just tweak what you have... you may have more going for you than you first realize.


2004-12-01, 22:57
"How hard is Silionylon to sew? I mean like slippery wise and such, some fabrics are very slippery and therefore hard to sew with a machine"

At first I found silnylon to be quite a challenge, and you don't want to pin it or you will create holes in it and the whole point of the stuff is that it is light and waterproof - right?

1.) I found that some (not all) masking tape will stick to it, so pieces can be taped together
2.) paperclips and report clips are great to hold folded seams and you can slide them off as you sew
3.) I found a glue - similar to a cassean glue (Elmer's glue) but gummier called "sew-no-more". It is intended to replace stitching on some fabrics..... won't stick that well on silnylon, but I can glue seams together, clip them with paperclips etc, and then stitch them. Makes a very strong, waterproof seam and it feeds through the machine much better than an unglued seam.
4.) I bought a "walking foot" for the sewing machine that grips the fabric from above and aids in feeding it through. Not that expensive and an accessory that you might consider if you plan on sewing a lot of it.

Hope this helps.

Hog On Ice
2004-12-26, 05:08
Some recent experience with hammocking in the cold:

Equipment used : Exlorer Deluxe A-Sym Henessy Hammock; full length Exped Down-filled Air Mattress (DAM); full length blue closed cell pad under DAM; 0 deg. F down bag - Feathered Friends Ibis - used as a quilt; 10 by 10 foot sylnylon tarp; a set of Army surplus polypro long johns that I use to stuff around my shoulders; a stuff sack filled with extra clothes for a pillow; a hotwater Nalgene in a sock.

Location : Black Rock Hut area of Shenandoah NP - one of the lower tent sites

Date : 24 Dec 2004 night (25 Dec 2004 morning)

Temperature : estimated 10 deg F - forecast was 12 deg F and I was up a bit in altitude

Wind : calm

Humidity : I was fairly close to a small stream and down in a hollow so it might have been a bit more humid than otherwise - the night was clear with a nice full moon

Clothing worn while sleeping : thin polypro hat liner, knit skull cap, Army surplus polypro balaclava, knit hat; light weight Capilene long johns; Army surplus heavy weight polypro long johns; nylon pants; heavy weight fleece pullover; glove liners; Brookdale hiker wool socks - note the hat system is due to the fact I use the sleeping bag as a quilt and as a result I don't use the hood of the bag.

Results: Basically I was warm and comfortable all night with the mild exception of my toes - I probably would have done better without the socks but since I usually need to get up a couple times in the night I left them on to avoid the hassle of putting them back on just to go water the bushes. The DAM did take a while to warm up and I felt the cold on my back and butt for about 15 minutes while the DAM was warming up - I may try a different arrangement in the future and put the blue foam pad on top instead of under the DAM for just this reason. I had a bit of problem with frozen condensation on the bug netting part of the hammock - it was thicker than I had expected and would rub off on my hat each time I got up - sort of a snow fall inside the hammock. There was also a fair bit of frozen condensation on the tarp both under as well as on top of the tarp. Since it was a clear calm night I probably should have done without the tarp and that might have helped with the condensation but I am not sure due to the condensation (dew) frozen to the upper surface of the tarp. One additional thing I am thinking of is to get a hammock without a bug net just for winter camping so as to avoid the issue of the frozen condensation rubbing off on my head as I get out of the hammock. Campsite selection was a problem also with the nearby water adding to the humidity - unfortunately due to the surrounding laurel and small trees I basically had to use one of the official tent sites and the one I used was the only one with a pair of trees good for the hammock.

2004-12-27, 05:38
Just a thought (it works for me).

I bought a windscreen (sorry windshield on your side of the Pond) heat reflecter. You may have seen them, the aluminium foil ones. Stuffed in the bottom of my hammock it reflects the cold out and keeps the heat in.

As it's wider than me (well for the moment!) it wraps around keeping the sides warm as well. They don't weight much and can be cut and duct taped together to custom fit you and your bag.

This setup has kept me warm on Dartmoor and the Brecons in mid January with temperatures well below freezing. Works well on the ground as well (which is where I originally 'discovered it'.

In keeping with everything having more than one function, it's also an excellent heat refector. Put it behind you when sitting in front of a fire and dry/warm both sides at the same time.

Bedford, UK

2004-12-27, 12:48
I have been using an REI "Pack and go" Hammock with a Pacific Outdoor Inflatable matress (like Thermarest but tapered head and foot) for 2 years now. Granted, I haven't used it in January, but it has kept me very warm in March in GA. My Clark and HH now sit in the closet.

2004-12-27, 15:00
I have the Pack N Go Hammock, I like it for lounging outside, tried to sleep in it with a pad in November, and I found it to be too small, but for sitting outside and reading a book it's great, I rig it under my deck

I got my HH a few days ago, spent two nights in it.

Night 1:
Started off with the Therm-A-Rest on the ground, didn't want it, I had my 30 degree lafuma bag, Had fleece hat, Heavy Fleece Shirt, Fleece Pants, and Wool Socks, Got colder and used the pad, kept me pretty warm, had a fleece bag at my feet. Overall I was ok warmish, but my feet were cold, I couldn't find my fleece socks. It got down to about 30 that night

Night 2
It was forcasted to get down to 16, so I decided to use two bags, I used my Lafuma 30 degree and a 60 degree, also had a pad under. Same clothing cept I used fleece socks and wool socks, my feet always get cold. I was really warm, it actually got down to 20 degrees, and I wasn't cold. Only problem that my outside bag was wet, due to condensation.

Overall I like the hammock, I emailed Tom about a problem with my HH's rope, the core is coming out, hopefully he can get that fixed. I have to say the HH and the snakeskins are ingenious, I like the HH more than my bed, but in the winter it's alot of work, can;t wait till it gets warmer.

Also, some people have mentioned about using a car sun window relfected to gain heat, I was at the dollar store, and they had one, so I picked it up, I might give it a try tonight.

SGT Rock
2004-12-27, 18:00
There are a lot of better working ideas than the sunscreen. You might want to look at a cover for under the hammock like the Supershelter or the JRB undershield or whatever it is called. I wrote a piece a while back about the fallacy of radiant reflectors.

2004-12-30, 08:25
Hi Katesdad

I've sent you a personal message - check your Inbox.



Blair Collins
2005-01-03, 02:56

I am new to this site but wanted to thank you for your posts.

I have a friend that has a HH and he loves it. After recently reading a review of the new super shelter, I became intrigued about how it would work in really cold environments. I used to climb a bit and was used to carrying my backpack condo (NF VE-25). I often wondered what I would do without all that weight. Having slept on a mountain with a deed to the world I realize that bivy sacks have their benefits. Having slept in a hammock on the beach in Costa Rica, hammocks do too.

Now the ultralight hiking trend has me intrigued. I am looking to find a gear set that is very flexible and rugged. I am willing to give up some weight for features that work.

This Fall I picked up and Ecotat Freedom Shelter with the intention of using it with a hammock that I carry in my pack. Using it as a poncho, tarp, bivy, a-frame or the hammock should make it veristile but ..... possibly cold. It gets down to -20F here or more in Jan/Feb so your conversation has really peaked my interest.

I can build snow caves and such but would really like to have a year round, system that can be set up and taken down in a wide range of settings.... the HH supershelter could be a great piece of gear.


Have any of you used the new super shelter in COLD weather? What did you think? What is your gear weight and size relative to bivy sac/tents?

Have any of you used the Ecotat shelter before? in COLD weather? Insights would be appreciated.

What tarps shelters have you used in conjunction with the HH to provide added wind/snow protection?

I see from Sgt. Rocks review that he has used the HH with treking poles in a bivy configuration. Have any of you done this in cold weather or on snow/ice? What is you luck above tree line? In wind? Heavy snow?

HOG ON ICE: Great posts! Do you have any pics? Very interested in you set up.

Great thread going here.

I look forward to hear and reading some more.

Wishing you all the very best,

Blair Collins

Hog On Ice
2005-01-03, 10:09
HOG ON ICE: Great posts! Do you have any pics? Very interested in you set up.

Sorry - I don't own a camera and as a result I have no pictures for you. The setup is very straight forward however - Hennessy Hammock Explorer Deluxe A-Sym with the Oware 10x10 sylnylon tarp rigged diagonally over the hammock (this replaces the HH supplied rain fly). Inside the hammock I have the Exped DAM on top of a Walmart blue foam pad. The FF 0 degree bag is stuffed up toward the head end of the hammock. The pads are oriented somewhat diagonally as where you want to sleep in a HH. Upon entry one sits on the fabric beside the pads, brings one's feet into the HH , pulls the bag down by one's feet, lifts feet onto pads, pulls butt up onto the pad, more around on the pad until in good position mainly so feet are on pad and pillow is under head and neck, adjust the extra clothing around shoulders so the shoulders and not in contact with hammock fabric, arrange bag and stick feet into the partially zipped up bag, pull bag up and tuck around your body, hang head lamp on ridge string, put on mittons and finish final adjustments to the bag, then go to sleep, sleeping on your back.

Blair Collins
2005-01-03, 11:20
Hog on Ice:

Thanks for the reply. I will look into the Exped DAM, sounds promising.


2005-01-04, 13:37
Havent tried it yet but the plan is... I have an old synthetic mummy bag thats starting to fall apart. I am going to cut the top off but leave 12" on top at the foot to stuff my feet into and hem the edge. The theory is it will keep my back and sholders warm. A closed cell pad and extra cloths has worked but I havent been out below 30 with it yet.

2005-01-30, 13:01
Stop by a construction site and see if they'll let you have some scrap. There should be pieces that are removed from window/door openings.

Major Slacker
2005-02-07, 23:53
I have seen people use a small peice of Tyvek under the hennesy hammock to serve as a little "door step" a place to sit on and place your boots on etc. Would you guys reccomend this?
I use a trash bag -- cheaper than Tyvek, easy to get, you can put shoes and things inside it, you can use it for maybe 100 other things.

SGT Rock
2005-02-07, 23:55
Trash compactor bags are good for this because they are very durable and they can be a dual use pack liner.