Neo XTherm too warm?
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David Poston
(dgposton) - F

Locale: Texas / Colorado
Neo XTherm too warm? on 10/13/2013 11:06:15 MDT Print View

This summer in late July, I was testing my new Neo Xtherm in the Colorado Rockies. Lows were around the high 30s-low 40s. Using my ZPacks 20 bag, I noticed that I often got way too warm. I'm normally a cold sleeper and have often been freezing cold with my BA Insulated Air Core and a 32 degree bag. When I was camped in the San Juans with temps likely in the high 30s I had to ditch my baselayers and sleep in my underwear and a short-sleeve synthetic tee for a while. I even had my bag unzipped. I did have some altitude sickness at the time, I'm not sure if my elevated heart rate was a contributing factor, but I was wondering if perhaps the Xtherm can be too warm for summer use? Should I stick with an Exped UL Synmat or the Neo Air Xlite?

I was hoping the Xtherm would be a do-it-all year round pad for me. Curious if others have had similar experiences. Another downer--the Xtherm seemed to leak air from the first night out. I was using a GG thinlight 1/8" underneath my torso to prevent punctures.

Max Dilthey
(mdilthey) - M

Locale: MaxTheCyclist.com
Hmm... on 10/13/2013 11:28:02 MDT Print View

Can't really be warmer than your body temperature.

In other words, it retains heat but doesn't put it out, so the sleeping bag or your altitude sickness may have been the cause. At any rate, one night is not enough to decide for yourself if it's good or not.

As for punctures, keep in mind that if you get off your pad and the air in it cools down, it feels deflated even though it isn't, since warm air takes up more space.

Edited by mdilthey on 10/13/2013 11:29:26 MDT.

Mark Ries
(mtmnmark) - M

Locale: IOWAHHHHHHHHH!!!!!!!!
Re: Neo XTherm too warm? on 10/13/2013 12:39:13 MDT Print View

I believe that more R-value under you is going to make you warmer just like more above you does. If it keeps you warmer in the winter it will keep you warmer in the summer also. Since the ground is cooler than us less insulation should make you cooler

Jennifer Mitol
(Jenmitol) - M

Locale: In my dreams....
Re: Re: Neo XTherm too warm? on 10/13/2013 15:46:01 MDT Print View

I have gone ahead and switched to my downmat UL 7 for all my trips. It makes no difference to me in the summer or the winter...as it doesn't make you any warmer than you already are. It does not generate warmth, and the ground is warm enough in the summer anyway such that less R value won't really provide any "coolness" anyway.

In an earlier thread on this topic someone mentiond that your mattress at home doesn't make you any hotter in the summer...

Javan Dempsey
(jdempsey)

Locale: The-Stateless-Society
Re: Neo XTherm too warm? on 10/13/2013 17:07:59 MDT Print View

You've probably just not had adequate bottom insulation in the past, and that's why you thought you were a cold sleeper.

Otherwise, your metabolism may have changed, but regardless, you were more than adequately insulated both top and bottom.


When making quilts it became very apparent to me that most people that experienced cold while sleeping at the appropriate ranges for their quilts, weren't insulating below properly. It's equally as important as top insulation, and most 3-season pads aren't adequate at freezing temps.


You'll probably be fine now with the Xtherm, and an appropriately rated quilt, i.e. a 30 degree quilt down to 30.

I've always leaned toward having more bottom R value than necessary, and I usually burn up in my 30 degree quilt even at 25 degrees.

Clayton Mauritzen
(GlacierRambler) - F - M

Locale: NW Montana
Re: Re: Neo XTherm too warm? on 10/13/2013 17:28:13 MDT Print View

Check out this thread.

FWIW, I have more than 20 nights out on my X-Therm since December. It's my year-round pad.

Rick M
(rmjapan) - F

Locale: Tokyo, Japan
Re: Re: Neo XTherm too warm? on 10/13/2013 18:55:26 MDT Print View

I've read in lab testing the parameters of the EN13537 test, it was determined that wind velocity, the ground insulating power of the mattress, and the time-to-loft of the bag will have the greatest influence on the temp rating.

Significant EN13537 standard test basics;
Wind velocity testing parameter: 0.5m/sec or <~2kph
Ground Mattress Insulaton parameter: 0.85 m2K/W or ~R5.1
Time to Loft parameter: 12hr

It was determined that even slight increases in wind will decrease the temp rating 2-3C, while a lower rated mattress can decrease the rating by up to 6C. A bag that cannot fully loft may affect the rating by as much as 8C!

Serge G.
(sgiachetti) - M

Locale: Boulder, CO
all season on 10/14/2013 03:36:10 MDT Print View

wow, interesting info on the EN tests, Rick. Reminds me of the recent bpl article about the effects of wind on insulation.

A mat can be 'hot' in the way that a sleeping bag is 'hot'. And the xtherm is in fact a hot (insulative) pad. Two ways to make the pad more appropriate for warmer weather--deflate the pad slightly, or use a lighter sleeping bag or quilt. With my katabatic chisos (+1 oz overfill) I'm able to use this combo for more than half the year in the CO rockies. I camped at a few high alpine lakes late last october in a hexamid with a katabatic sawatch and the xtherm, and I was uncomfortably hot. I haven't yet had the same problem though in the summer using my chisos lightly draped and the pad deflated.

So, I'd recommend the xtherm as an all season pad depending on what your sleeping bag/quilt quiver is. If you can't find a comfortable way to mate it with your 20 degree zpacks mid summer, than it would be less expensive and better weight savings to go with an xlite torso pad, than it would to buy a 1 season quilt.

I've used my xtherm as my all season pad for about 2 years, and durability has been great for me even after a sharp and rocky bivy on mount adams with no ccf pad. No leaks or punctures. I have found that I like vertical tubes better than the horizontal on the neo-air, but the warmth and lightness has made it a good investment.

Mark Ries
(mtmnmark) - M

Locale: IOWAHHHHHHHHH!!!!!!!!
Re: Re: Re: Neo XTherm too warm? on 10/14/2013 07:37:14 MDT Print View

The Rocky mtns in July when nights get down to what the OP states are gonna have a pretty cool ground temp I'd guess below 60. From 98.6 that's over half way to freezing. No a mat does not generate heat it slows the loss of heat just as the loft above you does not generate heat it slows the loss. Your mattress at home also makes you warmer in the summer although if it is room temp and that room temp is 75 it would cool you till you warmed its surface. Sleep in the same room in a fish net hammock or the same temp concrete floor you would be cooler than your home mattress.