U.S. patent application 20190038040 (applicant Technogel Italia S.r.l., Pozzoleone, Italy):
"Mattresses and mattress toppers having an upper layer including a high heat capacity material are disclosed. The mattress is configured to reduce a core body temperature of the body supported thereon, and thus induce improved sleep, measurable as an increase in the time spent in slow wave sleep relative to standard mattresses having lower heat capacities. The high heat capacity of the mattress may be attributable to the geometry and nature of the support material and optional additives, including polymer gels and phase change materials. Methods for improving sleep quality and uses of the high heat capacity mattresses to improve sleep quality are also disclosed."