On a whim I decided to go up to the top of a mountain here in Virginia to test out my new -15 degree MH Lamina sleeping bag. It was windier than I expected at the top so I decided to set up shop in the summit shelter with its concrete floor. It was probably no colder than 15 degrees but after a little bit I found myself very very cold in the bag.

I tossed and turned and found that I was warmer sleeping on my side, with less body contact to the pad. My first thought was to curse my sleeping bag but I'm thinking the culprit is my beat up blue Thermarest Ridge Rest. I slept on it for almost two months straight last year so it's taken some abuse.

Am I right in thinking that the absorbing power of the concrete was more than my poor Thermarest could handle? Should just I carry an inflatable with me?

Yup, I think you guessed it. An inflatable should treat you fine. Last time I used a Ridge Rest I noticed it was significantly colder than an inflatable.

Inflatable on top of the ridge rest is way warm even on top of wet snow!

Cheers -E

i like my big agnes insulated air core. it's comfy and keeps you off the ground.

Ridgerest pads do wear out over time. I tend to use gear until it's completely unusable, but after shivering every night on a 6 day Alpine Ice class on Mt. Baker a couple of years ago, and noticing the melt out shape underneath me in the snow, but not under my tent mate, I threw my (not sure how) old full-length Ridgerest pad away and replaced it with a new one. I was immediately much more comfortable and warm. This past summer I broke down and bought a Thermarest inflatable pad which is even warmer and more comfortable, but I still like the idiot & puncture proof qualities of the Ridgerest and figure I can use both if I do something really cold.

Ok, I think I'll invest in an inflatable and just stack that on top of my thermarest. I don't mind carrying the thermarest, it weighs nothing and lashes onto the outside easily and I guess it'll give the inflatable some protection. I tend to be pretty vicious with my gear.

I use a Prolite Plus Thermarest inflatable. It works great and I stay plenty warm. When I expect very cold temps I also place a pad under the Prolite Plus. It only weighs 24 oz.

You guys have odd experiences - a closed cell foam pad (i.e. a ridge rest) is substantially warmer than an inflatable pad. Much higher R value.

jschrock wrote:Actually not correct. Ridgerest R is 2.6 and Prolite Plus is 3.8.

I'm assuming that's for a new one (closed cell Ridgerest). I can tell you from experience that a 5+ yr old one is much lower than that....

Man, I've had my ridgerest for 15 years. I was about to buy a new one until I found the new unit weighed 1 ounce more.