I don't know if y'all are familiar with the PALS (Phillips Arctic Living System) but it seems like it's basic idea of using urethane foam inside breathable fabrics would work very well and rather cheaply as a DIY insulation system. It is bulky but fairly light and apparently can work in VERY cold conditions. I guess I'm wondering if anyone has seen or done this for hammock camping.
This is Jim Phillips (the inventor) page on how it works and why.
any thought at all?