Patent attributes
A mattress device has an foam body formed of a closed cell foam material which has a torso support area defining a recess having a recess bottom. An inflatable mat is disposed in the recess and insulated from a ground surface by the recess bottom. The inflatable mat is inflatable to rise above the top surface of the foam body. The foam body is preferably formed of a top foam layer having an aperture defining the recess and a bottom foam layer which provides the recess bottom. The bottom foam layer is formed from material having a higher insulation to weight ratio than material of the top foam layer, and the material of the top foam layer has a higher volume to weight ratio than the material of the bottom foam layer. The inflatable mat is optionally self-inflatable.
