title: Effect of a warm footbath before bedtime on body temperature and sleep in older adults with good and poor sleep: an experimental crossover trial.
abstract: BACKGROUND
  The decrease in core body temperature before sleep onset and during sleep is associated with dilation of peripheral blood vessels, which permits heat dissipation from the body core to the periphery. A lower core temperature coupled with a higher distal (hands and feet) temperature before sleep are associated with shorter sleep latency and better sleep quality. A warm footbath is thought to facilitate heat dissipation to improve sleep outcomes.
  
  
  OBJECTIVE
  This study examined the effect of a warm footbath (40°C water temperature, 20-min duration) on body temperature and sleep in older adults (≥55 years) with good and poor sleep.
  
  
  METHODS
  Two groups and an experimental crossover design was used.
  
  
  METHODS
  Forty-three adults responded to our flyer and 25 participants aged 59.8±3.7 years (poor sleeper with a Pittsburgh Sleep Quality Index score≥5=17; good sleepers with a Pittsburgh Sleep Quality Index score<5=8) completed this study.
  
  
  METHODS
  All participants had body temperatures (core, abdomen, and foot) and polysomnography recorded for 3 consecutive nights. The first night was for adaptation and sleep apnea screening. Participants were then randomly assigned to either the structured foot bathing first (second night) and non-bathing second (third night) condition or the non-bathing first (second night) and foot bathing second (third night) condition.
  
  
  RESULTS
  A footbath before sleep significantly increased and retained foot temperatures in both good and poor sleepers. The pattern of core temperatures during foot bathing was gradually elevated (poor sleepers vs. good sleepers=+0.40±0.58°C vs. +0.66±0.17°C). There were no significant changes in polysomnographic sleep and perceived sleep quality between non-bathing and bathing nights for both groups.
  
  
  CONCLUSIONS
  A footbath of 40°C water temperature and 20-min duration before sleep onset increases foot temperatures and distal-proximal skin temperature gradients to facilitate vessel dilatation and elevates core temperature to provide heat load to the body. This footbath does not alter sleep in older adults with good and poor sleep.
authors.affiliation: School of Nursing, Chung Shan Medical University, Taiwan; Department of Nursing, Chung Shan Medical University Hospital, Taichung, Taiwan. Electronic address: wcl@csmu.edu.tw.
authors.forename: Wen-Chun
authors.initials: WC
authors.lastname: Liao
authors.forename: Lee
authors.initials: L
authors.lastname: Wang
authors.forename: Ching-Pyng
authors.initials: CP
authors.lastname: Kuo
authors.forename: Chyi
authors.initials: C
authors.lastname: Lo
authors.forename: Ming-Jang
authors.initials: MJ
authors.lastname: Chiu
authors.forename: Hua
authors.initials: H
authors.lastname: Ting
mesh_terms: D001494:Baths; D001831:Body Temperature; D018592:Cross-Over Studies; D005260:Female; D005528:Foot; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D012890:Sleep
keywords: Body temperature; Foot bathing; Older adult; Sleep