Ground insulation.

Justin, you definitely need more insulation if it is at or below freezing. Your body heat is moving to the cold ground with not enough insulation to slow this process. If you are happy with a ZLite, you should get a ZLite Sol, which has a reflective coating to (theoretically) return body heat, increasing R-Value to 2.6. For freezing, you can then pair the new ZLite Sol with another pad to achieve something closer to an R-value of 4.5 – 5 R-value.

This second pad could be another closed-cell foam pad (but it might be harder to carry 2 bulky CCF pads), a self-inflatable (usually die-cut foam and air) or an inflatable (air tubes, with or without some insulation). The lightest of these would be torso-size.

I would shoot for a combination of pads that will get you an R-Value of 4.5 – 5 for freezing temperatures.

Completely agree with Steven. On the free side, do you ever try to increase the insulation of your pad with leaves, needles, straw, etc?

But convenience wise, another pad in combo would help A LOT. On a White mountain trip, my friend decided to use no pad, but just a space blanket type thing and a sleeping bag. Even though it only usually got down to 40's and 50's most nights, he was always cold.

Thanks Steven, I'll try the reflective z-lite.
I'm surprised that I haven't thought of my pad until now. 2 pads will be real bulky, I might consider an inflatable but I don't know if I can handle the initial cost, maintenance, and cost of replacement (poor college student).

Yes, I have increased my ground insulation with natural materials quite a few times. It's a very important survival skill to know. Sometimes you can't find anything to make a mattress from. You really need a dry grassy field, thick needle duff, or green branches from a blown over tree (if you want to stay lnt). It's not something I would rely on because it takes time and effort, but it's a good skill to know if it gets colder that expected or you get unexpected snow on the ground. Bushcrafty skills like that are a good substitute for over preparing.

Inflatable maintenance is for people who don't take care of their pads. I have literally hundreds of nights on a Thermarest All-Season, then later a Thermarest X-Therm. I've never even gotten a slow leak.

PM sent.

if you do get an inflatable i recommend you get a neo air variant … ANY inflatable can leak, while my original version is still going strong, ive seen other peoples inflatables have issues … a quick search of online reviews will show enough people having issues with all sorts of inflatables no matter what the brand

cascade designs is well known for their top notch service … or buy it from somewhere like MEC with a no questions asked warranty

if you do decide to get an inflatable, you can probably still use your old foam pad …

;)

Might I also recommend an Exped mat? I know there's a lot of love for the TR Exlight and Extherm, but Exped has a competing version for just a few ounces more that, at least in my opinion is much more comfortable. If you're worried about durability, the Expeds also seem much more durable. That said, as someone mentioned holes are for people that are more rough on their gear. I've had plenty of pads and never had a leak in any of them. Site selection and prep and good maintenance and storage and overall just taking care of your gear should eliminate 99.9% of holes or leaks you'd otherwise get.

Justin, to save cost look to geartrade.com. Lots of sleeping pads under $100. I think they even have a neoair trekker torso for around $70 (not UL, but still nice for winter). Lots of other brands too. Also don't forget REI garage sales. At the last one I found several pads for ~$20 and an Xtherm for $65.

Definitely upgrade your pad system. I went from a persistent cold sleeper to a very hot sleeper by swapping out to a warmer (and more comfortable) pad and learning to eat better (load up on fats for dinner). The weight difference in a warmer pad are as good, if not better, than extra down in a sleeping bag/quilt.

"if you're cold, put a hat on"

to some extent, if you're cold, it doesn't matter where you increase your insulation – better pad, better jacket, better hat,…

depending on ground temp, air temp, wind, what insulation you already have,…, there is probably an optimum place to add insulation and minimize added weight. Hat can be good because your head is warmer, loses more heat, smaller area so can provide the most warmth for the weight.

Not that getting a better pad isn't a good idea

you should absolutely be wearing a hat a cooler temps if you want to keep warm … and even more head insulation …

from "The Hot Brain", MIT Press …

Thermal Response to Cold

Cold does not exist as a physical entity in and of itself. It is defined as a lack of heat and is not a different form of energy. We are not "pierced" by the cold winds of winter. Cold is simply a sensation that results from heat loss. When humans are exposed to a cold environment, their skin cools and stimulates cutaneous cold receptors, which increase their firing rate as skin temperature decreases . This in turn activates neural pathways to produce superficial vasoconstriction, piloerection or "goose pimples," and possibly shivering. The superficial veins under the skin constrict, and blood returns from the limbs via deep veins, the venae comitantes. This venoconstriction contributes to the lowering of skin temperature, which reduces the temperature difference between the skin and the environment, thereby decreasing heat loss by radiation, conduction, and convection. In very cold weather, vasoconstriction is so effective that tissue insulation can be increased sixfold. This is equivalent to wearing a light wool business suit. Interestingly, the insulation of the head does not change with environmental temperature because cerebral blood flow is kept constant : at -4 C the amount of heat lost from the head is about half of that produced
by the body at rest. It is wise to wear a hat in the winter.

;)

2 pads will be real bulky, I might consider an inflatable but I don’t know if I can handle the initial cost, maintenance, and cost of replacement (poor college student).

Yeah, two full thickness CCF pads would be pretty bulky.

A couple of options:
1. Get a RidgeRest Sol instead of a Z-Lite Sol. The R value is slightly higher, 2.8 vs. 2.6. The weight on a Ridge Rest is ever so slightly lower too 400g vs. 410g, but you have to be a pretty serious gram weenie to get excited about 10g. :)
2. Get a GG Thinlight (or similar) and use it in conjunction with your primary pad. GG doesn’t list an R value, but I’m going to estimate it at about 0.5 to 0.8, which if used with a RidgeRest Sol would give you a total R value of about 3.3 to 3.6. An R value of 3.3 to 3.6 is still a little bit low for frozen ground, but I think it would be an improvement over an old battered Z Lite alone.

You could also supplement things with torso length pad and putting your backpack under your feet.

Just some ideas (based on a lot of cold nights), :)

HJ
Adventures In Stoving

pm replied :)

Thank you all for the suggestions.

I wear a cheap 2 oz acrylic beanie with a buff balaclava style, should I be wearing something warmer at below freezing?

I wear fleece beenie down to freezing

down to 20 F I wear an additional fleece balaclava, or I wear a synthetic balaclava

you can get a thick fuzzie beanie for like 5$ or so on clearance …

add that … and the hood on you puffy and yr good to go

;)

Is there any benefit to having a full length in colder weather? Or would it be a more efficient use of weight to just layer everything at the torso?

"Is there any benefit to having a full length in colder weather? Or would it be a more efficient use of weight to just layer everything at the torso?"

Yes and no.

If you do not have a full length insulation pad in winter, then the body parts that are hanging off the pad will get very cold.

In summer weather, I use one thickness of CCF foam pad. In winter weather, I use double that thickness. Often I will use two 3/4-length pads and overlap them in the middle. That way, all of me gets at least one thickness of padding, and most of me will get two thicknesses in the middle.

–B.G.–

For sleeping on snow I was thinking a full length and then 2 half length torso pads layered for the upper body. Do you think that would be overall warmer than 2 full lengths?

depends on your height .. for a foam pad you can always cut it, and use the extra as a sit pad or backpack "padding" when you want it

for inflatables … if you may be a short and stumpy azn like me, in which case a full length pad is kinda waste …, if you fit the women's pads yr laughing your head off as the neoair womens has a higher R value … unfortunately i bought my neo air years ago before they came out with the different models

remember that you can always put the pack, shoes and extra clothes under your legs … or curl up into a ball

or if you climb flake the rope under you

;)

"at -4 C the amount of heat lost from the head is about half of that produced
by the body at rest. It is wise to wear a hat in the winter"

http://www.livescience.com/34411-body-heat-loss-head.html

Yes, a full length pad is important in cold weather, and mandatory on the snow. For snow camping I use a full-length NeoAir Xlite with a 52" Z-Lite under my torso. My feet get a little cold from underneath but it's fine down to 10F or so with the right sleeping bag.

The Z-lite on its own is not a warm pad. A Ridgerest Solite is noticeably warmer. Back when I owned a Summerlite, I got cold at about 40F one night on the Z-lite but was comfortably warm in the same setup but on a Ridgerest Solite at 32F.

A good setup would be a Z-Lite Sol along with a full length 1/8" pad for camping on dry ground down to 25F or so. Add a full length pad for camping on snow.

http://www.livescience.com/34411-body-heat-loss-head.html

actually i would argue that the old army research probably applies better in every day winter situations

as ….

his heat-loss myth probably came from experiments in the 1950s, when military researchers exposed subjects to frigid temperatures. While their bodies were bundled up, their heads were exposed — and they were found to have lost more heat from their noggins.

sounds more like a scenario most BPLers would encounter than …

n 2006, scientists revisited the question. They tested subjects in cold water with and without wetsuits, sometimes with their heads out of water and sometimes with their heads submerged. They found that the head accounts for about 7 percent of the body’s surface area, and the heat loss is fairly proportional to the amount of skin that’s showing.

i dont know anyone who backpacks/climbs/etc underwater … not even in our rainy PNW …

now if one was a scuba diver and this was scubadivinglight.com … that would be a different story

either way if you are cold in winter, put something on yr noggine

also … in hypothermia situations the statement by the MIT press publication still holds true as far as i know … if you are cold enough to shiver you should probably put on a hat

Now, what about hypothermia and heat loss through the head?
If the hypothermia victim is not shivering, they are at rest, and the heat loss through the head remains about 7%. But, this is important, if they are shivering, the percent of heat loss via the scalp can increase to upwards of 55%, so protecting the head well is a very important part of treating the hypothermia patient. And as you can imagine, the primary defense against the cold and hypothermia is vasoconstriction of the peripheral circulation, this shunts blood to the core, reduces circulation to the skin, and increases the percent of heat loss through the scalp.

The difference is that the shivering hypothermia patient is indeed exercising, but they do not vasodilate the peripheral circulation; the shivering muscles increase metabolic demand and cardiac demand so the patients do increase their cardiac output; therefore, they do increase cerebral circulation; therefore, they do increase the percent of blood loss through their head.

http://wildernessmedicinenewsletter.wordpress.com/2007/02/14/heat-loss-through-the-head-and-hypothermia/

;)

That live science article was funny – the point of it was that they were "busting the myth" that half of heat loss is through head, that head is 7 percent of body area and heat loss is proportional to area

but they pointed out the myth was based on the "bogus" experiment where the body was bundled up and head exposed – in that case half of heat loss is from head

that is unintentional useful info for backpackers, if you're in your sleeping bag with head exposed, then putting a hat on will make a huge difference

Are the sol pads really that much warmer? I thought the reflective mylar thing was a myth.

I dunno how much was the reflective barrier and how much was because Ridgerests are warmer to begin with. Also my Z-lite is really old and somewhat flattened. But if their specs are true R2.2 vs R2.8 is a big difference.