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HOME > No.20, Feb 2020 > The Effects of a Mock Shelter Environment on Sleep

The Effects of a Mock Shelter Environment on Sleep

Are evacuation shelters too cold in winter?By Kazuyo Tsuzuki
Kazuyo Tsuzuki

Professor Kazuyo Tsuzuki and her research team at the Toyohashi University of Technology conducted an experiment on the nature of sleep in an evacuation shelter environment. This experiment was performed by creating a mock shelter in the university's gymnasium with four emergency blankets and a standard futon set. The results showed that the low temperature (5℃) inside the gymnasium affected subjects’ sleep and body temperature regulation, reducing sleep efficiency by 10% and increasing fatigue.

In the Building Environment Laboratory at Toyohashi University of Technology's Department of Architecture and Civil Engineering, researchers study the effects that indoor environments have on the people that live in these spaces. As part of this research, the laboratory lead by Professor Kazuyo Tsuzuki conducted an experiment on the nature of sleep in an evacuation shelter environment. This experiment was performed by creating a mock shelter in the university's gymnasium with four emergency blankets currently stocked for use in case of an emergency, as well as a standard futon set. The subjects’ quality of sleep with these bedding materials in the gymnasium was compared to that in their own beds. The results show that the low temperature (5℃) inside the gymnasium affected the subjects’ sleep and body temperature regulation, reducing sleep efficiency by 10% and increasing fatigue.

The last few years have seen an increase in the number of major disasters, with more people being forced to live in shelters and temporary housing. The Japanese Cabinet Office has published guidelines for managing evacuation shelters with reference to efforts in the Sphere Project, but these guidelines provide no detailed instructions regarding power outages or necessary bedding and heating. Evacuation shelters are often large and have an uneven distribution of heat inside them. Power outages can also be expected, which can mean a lack of heating and a drop in temperature at the shelter. The Architecture and Building Environment Laboratory saw a need to study how people live and sleep at shelters and temporary housing, and to investigate the effect of power outages. The laboratory created a mock evacuation shelter in the school gymnasium, and compared the subjects’ quality of sleep at this shelter with that in their own beds.

The results of the study indicate that emergency bedding did not provide sufficient thermal insulation, even when four of the emergency blankets were used from the gymnasium’s supplies. In terms of sleep quality, sleeping in the emergency bedding decreased sleep efficiency by 10% and left the subjects more fatigued than when they slept in their own beds. The details of this research were published in the Journal ‘ Energy and Buildings’ on November 4th.

Fig.1

This study was performed in the gymnasium in winter, and it was found that the low temperature (5℃) inside the gymnasium adversely affected sleep, decreasing sleep efficiency by 10% when using basic emergency blankets which provide limited insulation. Further activities going forward include looking into providing down jackets to wear in addition to the emergency blankets, as well as other realistic ways to help regulate body temperature and improve sleep in order to prevent deterioration in people’s quality of sleep at low temperatures.

This study was made possible by a grant (H30) from the Hibi Science Foundation, to whom we are greatly indebted. The study was also supported by JSPS KAKENHI Grant Number JP19H02296 from the Japan Society for the Promotion of Science (JSPS).

Reference

Tsuzuki, Mochizuki, Maeda, Nabeshima, Ohata, Draganove, "The effect of a cold environment on sleep and thermoregulation with insufficient bedding assuming an emergency evacuation", Energy and Buildings, Nov. 2019, 10.1016/j.enbuild.2019.109562

避難所模擬環境が睡眠に与える影響

冬の避難所は寒過ぎる?
By 都築 和代

豊橋技術科学大学建築・都市システム学系 都筑和代教授の建築環境工学研究室では、室内環境が居住者に及ぼす影響に関する研究を実施しています。その中で、豊橋技術科学大学の体育館を使用し、避難所模擬環境での睡眠実験を行い、現状具備されている災害救助用毛布4枚と一般的な布団1組を使用して就寝した場合を自宅睡眠と比較しました。その結果、体育館内の低温(5℃)が睡眠と体温調節に影響を及ぼし、睡眠効率を10%低下させ、疲労感を増やすことを明らかにしました。

近年、大規模災害の発生率が高く、避難所や仮設住宅等で生活が強いられる場合が増えています。スフィア・プロジェクトを受けて内閣府が「避難所運営ガイドライン」を公表しているが、具体的な寝具や温熱環境、停電時等については記載されていません。避難所などの大空間は不均一熱環境になりやすく、また、停電も起こると考えられ、非暖房ゆえに低温になると推測されます。そのため、非住宅や仮設住宅での睡眠や生活環境を想定した研究や停電時を想定した研究が必要であると考え、大学の体育館を使用し、避難所模擬環境での睡眠実験を行い、自宅での睡眠と比較しました。

その結果から、体育館に具備されている災害救助用毛布を4枚使ったとしても断熱性が不十分であり、普段の睡眠に比べ、睡眠効率を10%以上低下させ、疲労感を増すことが明らかになりました。

今回の実験は、冬の体育館での低温(5℃)は、災害救助用毛布という限られた寝具を使用した場合、10%睡眠効率を低下させたことを示し、低温は睡眠に悪影響を及ぼすことが明らかになりました。今後は、低温での睡眠を悪化させないために、災害救助用毛布に加え、現実的なダウンコートなど着衣による体温調節補助や睡眠支援について検討していきたいと考えています。

この研究は公益財団法人 日比科学技術振興財団の研究助成(H30)を受けて実施されました。財団関係者の皆様に心より感謝いたします。また、本研究は現在、科研費(19H02296)によってサポートされています。

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Researcher Profile

Kazuyo Tsuzuki
Name Kazuyo Tsuzuki
Affiliation Department of Architecture and Civil Engineering
Title Professor
Fields of Research Buidling environmental engineering / Environmental ergonomics

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