title: Influence on human sleep patterns of lowering and delaying the minimum core body temperature by slow changes in the thermal environment.
abstract: OBJECTIVE
  We hypothesized that appropriate changes in thermal environment would enhance the quality of sleep.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Healthy young men (n = 7, mean age 26 years).
  
  
  METHODS
  Nocturnal sleep structures in semi-nude subjects were compared between a condition where an ambient temperature (Ta) of 29.5 degree C was maintained throughout the night (constant Ta), and a second condition (dynamic Ta) where Ta changed slowly within the thermoneutral range (from 27.5 C to 29.5 degree C).
  
  
  RESULTS
  Statistically significant (P < 0.05) results included a lower and a later occurrence of minimum core body temperature (Tc), and a longer duration of slow-wave (stages 3+4) sleep in dynamic versus constant T. However, total sleep time, sleep efficiency, the total durations of light (stages 1+2) and rapid eye movement sleep, and the latencies to sleep onset, slow-wave sleep, and rapid eye movement sleep did not differ between conditions.
  
  
  CONCLUSIONS
  Lowering the minimum and delaying the nadir of nocturnal Tc increases slow-wave sleep (probably by an increase of dry heat loss); use of this tactic might improve the overall quality of sleep.
authors.affiliation: Exercise Sciences Research Group, Tokyo Metropolitan Institute of Gerontology, Itabashi, Tokyo, Japan.
authors.forename: Fumiharu
authors.initials: F
authors.lastname: Togo
authors.forename: Seika
authors.initials: S
authors.lastname: Aizawa
authors.forename: Jun-ichiro
authors.initials: J
authors.lastname: Arai
authors.forename: Shoko
authors.initials: S
authors.lastname: Yoshikawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ishiwata
authors.forename: Roy J
authors.initials: RJ
authors.lastname: Shephard
authors.forename: Yukitoshi
authors.initials: Y
authors.lastname: Aoyagi
mesh_terms: D000328:Adult; D001831:Body Temperature / Q000502:physiology*; D004777:Environment; D006801:Humans; D008297:Male; D017286:Polysomnography / Q000379:methods*; D012720:Severity of Illness Index; D012890:Sleep / Q000502:physiology*; D013696:Temperature