View Full Version : Keeping a hammock cool

2006-07-10, 23:07
I also posted this at WhiteBlaze, but I thought, "redundancy can't hurt; it works for NASA!" :biggrin:

Maybe I'm missing something in the archives. If I am, I apologize to Just Jeff ahead of time :biggrin: I see tons of threads on how to stay WARM in your hammock, but no really good tips about how to stay COOL!

I took my brand new HH UL Asym out last weekend. It was incredible! I had NO setup issues, NO stretching issues, NO tarp issues...basically, it worked exactly as it was supposed to. Somehow I managed to skip every difficulty I've read about in forums. Other than the problem mentioned below, I had the most comfortable nights' sleep I've EVER had on the trail!

I only had one problem (well...a minor second problem, but that was just me being an idiot). I'm in North Carolina. The summers here get insanely hot and humid, unless you're in the mountains (and many times even there). My first hammock trip was to Uwharrie National Forest, just south of me (Greensboro). The nights were 75-80 F, relatively normal for this time of year. Also 70+ % humidity. The first night, I knew there was no rain expected, so I left the tarp off. I still felt like I was boiling alive. The second night I used the tarp and I was near miserable. I'm a VERY warm-natured person; I generally leave the thermostat on about 65 F in my bedroom so I can sleep comfortably.

The hammock just didn't feel like it was breathing near as well as I'm used to. By the way, my previous shelter was an MSR Trekker Tent, sans insert.

Any tips, observations, or helpful fingers to point out obvious newbie mistakes? :biggrin:

Just Jeff
2006-07-10, 23:32
Well, if it's hot, then there isn't much you can do about it other than finding a spot that isn't so hot...it's all about site selection. I have this little blurb at the bottom of my staying warm page:

When selecting a site to stay cool in the summertime, look for sites that are:

Exposed to the wind:
-No natural windblocks
- On top of a hill or ridge
- On the windward side

In the bottom of a valley to be in the "cold sink"

Near running water

Oriented in-line with wind direction (use tarp to "catch" the wind)

Other than that, you might consider making a hammock from a more breathable material...most of mine are untreated ripstop nylon (i.e. not DWR). I guess skeeters could bite through them more easily than the HH material (depending on which HH model you have), but soaking in permethrin would solve that issue if you're not averse to chemicals.

Maybe you could get a soft-sided nalgene cantene and fill it with cold mountain stream water and use it like a "cold water bottle" just like folks use them for hot water bottles - good on the neck, hip, etc.

Maybe someone else has other ideas?

I'll post this over on WB, too.

2006-07-10, 23:39
One little trick for staying a bit cooler in the hammock is to make your
rainfly into an air deflecting scoop. If you pitch the foot end of the hammock
directly into the wind, set the tarp low to the ridge line and low and fairly
close to each side of the HH. Then using a separate piece of string, remove
the foot end of the tarp from the main hammock line and raise it up a few
feet and tie off to the foot end tree. What you achieve is a ram air
scoop to funnel even a small breeze down into your hammock and out under
the head end. It works good unless you have hot humid rainy weather
or of course no air movement at all. But it is a simple solution for other
scenarios where the hammock is a bit stuffy or baking in too much sun.
Give it a try in the backyard, it is pretty impressive how much air you
can direct even in a light breeze.

Just Jeff
2006-07-10, 23:47
Haha - I think Turk's smarter than me...that's what I meant by "use tarp to "catch" the wind". Didn't realize it had a name!

2006-07-10, 23:51
Great ideas...I'm going out again this weekend, so I'll try some.

Turk - I'm also going to try my pulley suspension idea...any last-minute suggestions/warnings?

Jeff - It sounds like Turk might have a thing for cars, too :biggrin: If so, I'm right there with him!

2006-07-11, 00:09

Good luck with the pulleys. As you mentioned getting the right size for the
1/8" spectra cord on the HH is quite agravating. I work in a plumbing and
heating shop so I was able to order an aluminum 1" adjustable pulley used
for gearing down small vent motors. To get my ascender to work I had
to use another custom pulley for HVAC, drilling out the original and installing
my new smaller one and new cotter pin. I wouldnt use it for climbing now,
but it worked okay with the hammock. Hope you can post up some pics
on the rig you end up using. Would like to see.

Just Jeff. Ya, you were spot on in pitching into the wind. But when I
first starting using a hammock I didn't quite understand just how to
make the air funnel and wasnt quite clear on some of the terms the
veteran hammockers were using.=. Somebody here on the forums
put it into a little pic for me. Hmm .... here it is.
a pic of the set-up, for hammock newbies:

2006-07-11, 08:23

Good trick...

Even on a windless night this trick will work....Select a site high on the normally windward side of a mountain....the rising thermals will actually creat a breeze...best effect, off set the tarp further to the windward (normally west in northern hemishere) and gather more thermal...this will also dump the breeze more fully on the body core.


Just Jeff
2006-07-11, 10:24
Excellent pic, Turk...thanks for posting it.

2006-07-11, 15:37
There is a lot of cooling by evaporation gear in bragade quartermaster. I am not sure how good it is, but you may be able to rig a hammock cooler using something like that.

2007-01-30, 17:26
i can tell you all it gets hot in the swamps of louisiana,and turk's post is right on there is always a cool side in a HH.
i would add a wet towell hung on the centerline helps as a wipe for a little evap.

I had gained the summit of a commanding ridge, and, looking round with astonishing delight, beheld the ample plains, the beauteous tracts below.
Daniel Boone

2007-01-30, 18:16
If it is too hot to SLEEP AT NIGHT, it is most assuredly too hot to hike, stay at home and enjoy the AC, that's my technique anyway, I figure I've sweated and suffered quite enough.

2007-01-30, 21:47
I know, I know - sounds ridiculous!

I bought one of those little toy-like fans for $1.99. It's 4.5" tall x 1x1.5 & weighs 4oz. It has tiny, soft, flexible plastic blades (and really moves the air for something its size) in a tent.

Never tried it in a hammock, but I'm gonna -- It gets hot in FL too!

It has a small lanyard hole in the end opposite the fan blades, so it hangs from a loop in the roof of a tent (or hammock ridgeline!!!!).

Like I said, sounds crazy, esp for Ultralighters!

2007-01-30, 23:38
We hike to the snow pack when especially hot. I can always find a frozen slab of snow thru our summer months out here. Scoop out some ice, pick out the debris, and make some everclear and crystal light slushies. A couple of these and you will be sleeping on the ground, not caring about the heat!:evil:

2007-01-31, 20:49
Don't forget to open the windows on an under quilt when the weather turns hot.:biggrin:


2007-01-31, 20:59
when the weather turns warm, I plan to test out the JRB weathershield as
a stand alone underhammock insulation system. It has to be better than
my previous DIY attempts with poly plastics, glad garbage bags and tyvek.

Thinking that lining it with dry leaves will be perfect for those late spring/early
summer nights with just a top quilt.

2007-02-01, 00:40
I know, I know - sounds ridiculous!

I bought one of those little toy-like fans for $1.99.

Not a bad idea! Perfect for hanging from a hammock ridgeline.

I suffer from tinnitus so I like to sleep with some kind of white noise generator, ie fan. I recorded my A/C and spliced it into an hour long .mp3 that I play through lightweight clamshell speakers when I camp. Provides white noise but no cooling! White noise is also good for softening spooky nighttime noises.

Only downside is if you fall asleep while running one of those fans the batteries will be dead by morning. So that's a pair of AAs per night of camping... The mp3 player can last a couple of nights on a single AAA...

Not to mention rolling over carelessly forgetting about the fan and getting your hair tangled in the fan blades... :argh: