Winter air mattress AND closed cell foam pad

“Matt’s comments do not cover several other reasons for putting the foam underneath“

Precisely.  Those particular reasons, albeit very important considerations, would not affect the thermal conductivity.

And thank you for clarifying the difference between air-only and insulated air mattresses. (I was referring in particular to Neo Rest mattresses which depend  on emissivity to a certain degree.)

Here are the details for what I used on the trip at -35F. Also am including info on what how I changed that on a trip I just came back from using same equipment but slightly modified to see how performance went.

On my original post here is what I used to camp out with at -35F.

I slept under an open lean-to tarp.

Sleeping bag- WM Kodiak Down rated @ 0F covered with an  REI Gore-Tex bivy sack. This bivy is probably 20 years old but had only been used several times previously. This bivy is open at the top and does not completely close at the top.

Inside the bivy sack I placed the Thermarest ZLite pad on the bottom and on top of that was a Thermarest Neo Air XTherm pad.

Inside the WM bag I used a Sea To Summit Extreme bag liner. I was wearing Smartwool midweight thermal underwear on my legs with WM Flight pants. On my feet I had a single pair of Smartwool mountaineering socks with WM down booties.

On my upper body I wore a Patagonia Capilene thermal weight hoodie and another merino wool lightweight shirt. I pulled the lightweight hoodie over my head an covered it with a fleece hat.

During the night I had to remove the down pants as I was becoming too warm. I was more than comfortable throughout the night and into the morning. I am not talking survival here, I am talking comfort. The last thing I wanted to do was backtrack 11+ miles to the road and another 3 miles to my house (unless I could get my wife to pick me up @ Zero dark 30) at the road. (that ain’t happening)

As I mentioned, IMHO, it’s all about hydration and nutrition with a little bit of confidence in ones ability to adapt to the conditions. If you think your going to be cold, you will be cold?

I just returned from another another 2 day trip into the mountains 30 miles north of Fairbanks. I solo hiked in 12 miles pulling a pulk sled with 36lbs of gear. While this elevation was only at 2330′, the conditions are not forgiving as high winds are prevalent for this area. I camped in the snow surrounded by small black spruce trees with 5 feet of snow on the ground. Luckily there was only a sight breeze (3-5 MPH). The temps dropped to -28F the first night. I did not run into anyone other than one dog musher early on the trail and the isolation is what makes these trips all the more fun.

My setup changed a little for this trip. Instead of a tarp, went with my Black Diamond FirstLite 2lb single wall mountain tent sitting on a stomped out pad in the snow. I used the same bivy sack inside the tent (while most here seem to people disagree with). I shit-canned the Themarest Neo Air pad and only carried the ZLite pad this time. Used the same WM down bag but did not use the Sea to summit liner nor the down pants although I did wear the down booties. On my legs were the same single layer Smartwool bottoms and the same two layers on my upper body.

I slept plenty warm even without the NeoAir pad below me. It was a little bit harder on the body without the loft of the air mattress, but it was more than tolerable.

My hydration and nutrition did not change. Eat when you don’t feel hungry and drink fluids even though you don’t feel the need.

I did not use my stove at all inside the tent. Instead of bringing my MSR XGK multi fuel stove, I carried a Kovea Spider gas stove with a 1Lb bottle of propane gas. Propane has minimal issues at extreme cold temps and is safer if used inside a tent. IMO, the weight difference is minimal in comparison to the MSR liguid gas stove. A single 1lb bottle of propane will last over two nights and mornings boiling countless liters of fluids and still have gas left over.

Do you all not agree that going out somewhere where there is little interaction with others makes things all the more interesting? I am always aware of my surroundings and have complete confidence in my skills. That’s not saying that something can’t go wrong while you’re out there, because you know it can and it will. That’s part of the learning process and building of ones confidence in extreme conditions. I am 57 years old with a lifetime of endurance sports behind me as well as having spent a fair amount of time in the mountains of Alaska.

While I know there are others that will disagree with what and how I use the gear I’ve chosen, that does not concern me. To each his own. What works for me may or may not work for you. Go out there and experiment with what does and does not work. That’s what make it adventurous. Hopefully I have supplied you with what you needed more info on. Now go out there and have fun.

I will get around to posting a few pictures.

Sorry but couldn’t post all pics at once for some reason. First two pics are from first trip and all the rest are from trips into the mountains.

What David said: whatever doesn’t slide around.

This winter in the snow I’ve been using a low R value 3/8 roll foam military surplus matt on either side of Klymit inflatable insulated Static V Lite and to keep everything from slipping sandwiched a Gossamer Gear Thinlight 1/8″ between them.  The rest of the story is light thermal tights and fleece pajama bottoms, medium flannel shirt, inexpensive 15 deg bag.  Comfy at 20 deg on the snow.

What David said: whatever doesn’t slide around.

To keep everything from slipping sandwiched a Gossamer Gear Thinlight 1/8″ between the foam pad and air mattress.  The rest of the story is light thermal tights and fleece pajama bottoms, medium flannel shirt, inexpensive 15 deg bag.  Comfy at 20 deg on the snow.

Thanx for the update on the gear used Jon

I’ve always used a ccf pad and air mattress combo in the winter, which pad is dependent on expected temps

Recently I starting bringing a 40×80″ pad on my winter trips- this almost fills my small 4 season tent (BD Firstlight) perfectly- having a thin insulating layer over top of snow is really nice- no more hands/elbows/knees/feet directly on a thin layer of nylon and snow, my gear, clothing, boots all on top now as well

It’s definitely a bit of a luxury, but one that I don’t see giving up :)

We haven’t gone quite as far (or big) as MikeM, but we do carry foam ‘sit-upons’ and always sit or kneel on them rather than directly on the groundsheet on the snow. Same thing really.

Cheers

My winter air mattress is an REI FLASH All Season with a 5.3 R rating. That should be enough to take me comfortably to 0 F. by itself with my -20 F. down mummy bag.

By “best” combination of CCF and an insulated air mattress I originally meant warmth. But I also see David Thomas’ point about the combo that prevents you from sliding off the other mat being very important. So far the RidgeRest beneath the air mattress has been good in that respect.

Since I inflate my air mattress with a valve-compatible dry bag the air that goes in is ambient temperature and not warmed by my lungs. Therefore it stays at pretty much the same volume all night. That means it could be used on the bottom if I wanted to without it deflating as the night air cooled.

I really like the air bag pump for many reasons, not the least of which are the fast inflation and not getting dizzy st 9,000+ feet, which would happen if I was blowing it up with my lung power.