The well-known problem of outing with hammock is cold butt syndrome. It’s the name when your behind gets really and painfully cold from too much sleeping in a hammock on a freezing day without proper liner. Actually, there are many ways to fend off cold temperature. We can use a sleeping back, sleeping pad, or quilts. Sleeping back will make you warm, but just give a little room to move. Moreover, the sleeping pad often shifts when we sleep on it. The quilt or liner, upper or lower, can be the alternative. It traps heat, has no compression, easily to adjust, has large area coverage, and you can share it with others.