Had my wife sew a nylon bottom on my hammock. Then I sprayed adhesive on some cheap mylar on a 40X60 (cut to shape) piece of 1/4 foam from Oware. Slipped the foam between the hammock and bottom. To add warmth I put a 3/4 Ridgerest under the foam where my bottom would be. That and my down bag kept me quite toasty at 21*
Then I tried crawling in between the two layers. I turned the hammock upside down so I had my weight on the hammock and not on the added piece. I was roasting!! I need to work on the condensation build up some, but I think Ive found my all season set up that cost about a total of $20.