A flexible cellular foam or fabric product is coated with a coating including highly thermally conductive nanomaterials. The highly thermally conductive nanomaterials may be carbon nanomaterials, metallic, or non-metallic solids. The carbon nanomaterials may include, but are not necessarily limited to, carbon nanotubes and graphene nanoplatelets. The highly thermally conductive nanomaterials may include but are not limited to nano-sized solids that may include graphite flakes, for example. When coated on a surface of flexible foam, the presence of nanomaterials may impart greater thermal effusivity, greater thermal conductivity, and/or a combination of these improvements. The flexible foam product may be polyurethane foam, latex foam, polyether polyurethane foam, viscoelastic foam, high resilient foam, polyester polyurethane foam, foamed polyethylene, foamed polypropylene, expanded polystyrene, foamed silicone, melamine foam, among others.