Multiple-layer bedding materials and the effect of air spaces on ‘wet’ thermal resistance of dry materials

Variables affecting the ‘wet’ thermal resistance of infant bedding materials arranged to simulate use are identified. Thermal resistance was determined when the materials were flat, and also when spaced to simulate use, using a guarded-hotplate similar to that specified in ISO11092:1993(E). The relationship between ‘wet’ thermal resistance and thickness is explored, and the effects of increasing thickness of the air space under and among the various layers of bedding were determined.