Thermolite reactor sleeping bag liners - thoughts?

[Joynz]

I’m doing an overnight hike this weekend. Bush camping where there might be a frost.

I have a minus 6 comfort quilt and a R4 mat (and thermals and a hat to sleep in),

Am also considering getting one of the Thermolite reactor sleeping bag liners - which say they can increase warmth by up to 8, 11 or 15 degrees depending on the model.

Weight is 250g approx up to 400g.

What do you think?

[Zapruda]

I think these are far too heavy for a minimal weight increase. Wear your down jacket to bed or even your rain jacket. Boil some water and fill up a bottle and keep it close to your femoral artery.

[Petew]

As Zapruda said, down jacket will add way more warmth. Personally I haven't used a liner in years, too tangly....

[johnrs]

Hi Joynz, we used these on a very cold Nepal trip last year.
Initially a bit dubious but they do add many degrees to your bag/sleep system rating, quite a useful extender really.
The increase might might be nearly true to label
John

[Huntsman247]

Just wondering here... If you're expecting a possible frost only and you have a quilt comfort rated to -6 & an insulated mat do you really need to make it any warmer? Even for a cold sleeper that should be sufficient....

[CBee]

I use the extreme one, combined with a +4 bag, in below zero temps. Happy with it. Also I use it standalone mid season.

[Joynz]

Thanks all for the feed back.

It seems like opinion is reasonably split.

[bobcrusader]

I use one mostly to protect the sleeping bag and mat (I use a quilt, so its nice to have something between the mat and me beyond just thermals). I do find I can get by with a warmer rated sleeping bag, so end up at about the same weight, but less to wash when I get home. Silk ones are more expensive and don't add any warmth.

[Tino B]

I have the middle one - works well if you don’t have down pants and jacket with you. Good under a quilt to keep drafts out. Good as a bag in warm weather when you just need a light bag. That said, I tend to use Montane Prism pants and a Montbell down hoody as camp clothes and to boost a 30F quilt down to -5c or so.

[Joynz]

I like the idea of something between the mat and me too, as I have a quilt.

However, my quilt (-4 not -6 as I originally thought) was warm enough at the same time last year on the same hike even without wearing a jacket to bed...but sounds like it will be cooler this time.

[camm]

I've got the middle one. I use it primarily as a sacrificial (and washable) layer to keep my mat and my quilt clean. It does add a bit of warmth, mostly by taking the sting out of any draughts from tossing and turning. It also adds some weight and bulk, but less weight and bulk than a set sleeping clothes.

[Nuts]

I was going to say that warmth isn't subjective but then it probably does come across that way given it's a 'feeling'

Otherwise, as I understand, adding thickness of trapped air space adds warmth. In which case adding a dense matted material seems a poor option compared to the same weight of fluffy down. A thicker sleeping quilt, a sleeping bag or light down clothing (as mentioned above)? I've used the original (8c) S2S liner and can't imagine it making a winter bag from a summer bag.

[Nuts]

We don't use them anymore either but these are a very similar feel, thicker, well made and cheap: https://www.ebay.com.au/itm/Thermal-Sle ... ctupt=true

They are a bit heavier. But let's rate them adding 20c..

[Joynz]

Nuts - are they a stretchy knit fabric?

[Nuts]

yes, woven stretchy fabric