Mattress assemblies including at least one encapsualted panel including a heat absorbing material

A mattress assembly comprising:

• a single encapsulated planar panel proximate to a sleeping surface of the mattress assembly spanning at least a portion of the length and/or width of the sleeping surface and overlaying a core layer comprising:
• an outer layer comprising a liquid impermeable and flexible material completely encapsulating an interior region, the interior region consisting of a layer of liquid permeable fibers saturated with hundreds of grams of a phase change material that is not microencapsulated, wherein the interior region is free from foam, wherein the phase change material in a liquid state is configured to wick into and/or fills voids within the liquid permeable fibers, and wherein the single encapsulated panel is configured to extend the effective solid to liquid or liquid to solid transition time of the phase change material throughout an entire sleep cycle of 8 hours or more.