The effects of two different kinds of quilt on human core temperature during night sleep

Effects of two kinds of quilt with different thermal insulation properties between the upper and lower halves on human core temperature during night sleep were compared at an ambient temperature of 16 degrees C and a relative humidity of 50% in five healthy adult women. One quilt has a thick part (110 mm) in the upper half and a thin part (63 mm) in the lowest half (Quilt A), and the other has a thin part (63 mm) in the upper half and a thick part (110 mm) in the lower half (Quilt B). Subjects, wearing shirts with half-sleeves and breeches, slept on a bed with sleeping mat, being fully covered by either Quilt A or Quilt B from 22:00 to 06:00. The major finding was that rectal temperature fell more quickly in Quilt B after retiring at 22:00, being kept at a lower level during one third of the whole night. We suggest that the reduced level of rectal temperature in Quilt B might be ascribed to lower thermal insulation in the upper half side of the Quilt B and partly to different core-peripheral blood redistribution in the lower extremities between the two kinds of quilt. Rapid fall and lowered level rectal temperature in Quilt B might be of significance for ease in sleep onset and sleep depth.