Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2012 May 31;31(1):14.
doi: 10.1186/1880-6805-31-14.

Effects of thermal environment on sleep and circadian rhythm

Kazue Okamoto-Mizuno  1 , Koh Mizuno
Affiliations
Review

Effects of thermal environment on sleep and circadian rhythm

Kazue Okamoto-Mizuno et al. J Physiol Anthropol. .

Abstract

The thermal environment is one of the most important factors that can affect human sleep. The stereotypical effects of heat or cold exposure are increased wakefulness and decreased rapid eye movement sleep and slow wave sleep. These effects of the thermal environment on sleep stages are strongly linked to thermoregulation, which affects the mechanism regulating sleep. The effects on sleep stages also differ depending on the use of bedding and/or clothing. In semi-nude subjects, sleep stages are more affected by cold exposure than heat exposure. In real-life situations where bedding and clothing are used, heat exposure increases wakefulness and decreases slow wave sleep and rapid eye movement sleep. Humid heat exposure further increases thermal load during sleep and affects sleep stages and thermoregulation. On the other hand, cold exposure does not affect sleep stages, though the use of beddings and clothing during sleep is critical in supporting thermoregulation and sleep in cold exposure. However, cold exposure affects cardiac autonomic response during sleep without affecting sleep stages and subjective sensations. These results indicate that the impact of cold exposure may be greater than that of heat exposure in real-life situations; thus, further studies are warranted that consider the effect of cold exposure on sleep and other physiological parameters.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Effects of humid heat exposure at different segment of sleep on thermoregulation. Experiments 1 (26°C 60%RH stable (26), compared with 26°C 60% in the initial segment and 32°C 80%RH in the later segment of sleep (26����� 32)) and experiments 2 (26°C60%RH stable (26), compared with 32°C 80%RH in the initial segment and 26°C60%RH in the later segment of sleep (32 → 26)).. Reprinted from Okamoto-Mizuno K, Tsuzuki K, MizunoK, Iwaki T: Effects of partial humid heat exposure during different segments of sleep on human sleep stages and body temperature. Physiol Behav 2005, 83:759–765 with kind permission from Elsevier.
Figure 2
Figure 2
Changes of heart rate and high frequency, percentage of low frequency and ratio of low frequency to high frequency components in three conditions. The vertical line represents the standard error. *indicates the significant level after Friedman test; P <0.05. †indicates the significant level after Scheffe’s post-hoc test; P <0.05. Reprinted from Okamoto-Mizuno K, Tsuzuki K, Mizuno K, Ohshiro Y: Effects of low ambient temperature on heart rate variability during sleep in humans. Eur J Appl Physiol 2009, 105:191–197 with kind permission from Springer Science and Business Media.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Gilbert SS, van den Heuvel CJ, Ferguson SA, Dawson D. Thermoregulation as a sleep signalling system. Sleep Med Rev. 2004;8:81–93. doi: 10.1016/S1087-0792(03)00023-6. - DOI - PubMed
    1. Hasler G, Buysse DJ, Klaghofer R, Gamma A, Ajdacic V, Eich D, Rossler W, Angst J. The association between short sleep duration and obesity in young adults: a 13-year prospective study. Sleep. 2004;27:661–666. - PubMed
    1. Dew MA, Hoch CC, Buysse DJ, Monk TH, Begley AE, Houck PR, Hall M, Kupfer DJ, Reynolds CF. Healthy older adults’ sleep predicts all-cause mortality at 4 to 19 years of follow-up. Psychosom Med. 2003;65:63–73. doi: 10.1097/01.PSY.0000039756.23250.7C. - DOI - PubMed
    1. Manabe K, Matsui T, Yamaya M, Sato-Nakagawa T, Okamura N, Arai H, Sasaki H. Sleep patterns and mortality among elderly patients in a geriatric hospital. Gerontology. 2000;46:318–322. doi: 10.1159/000022184. - DOI - PubMed
    1. Parsons K. Human Thermal Environments. Taylor & Francis, Oxford; 1993.