Here you go
Originally Posted by gmcttr
I've followed many IX UQ threads, searched several times and I still haven't figured out what an "InsulTubes 2'x3' sewn-in Torso Heater" is.
Please explain for the search impaired. Thanks.
Basically long ridges sewn into the IX so that the layers maintain a gap.
And because a picture is worth a thousand words, I believe that Redoleary's video
shows the InsulTubes too.