OBJECTIVE: This study investigated the psychological and physiological effects of using sleeping bag-shaped aluminum sheets during night-time sleep in winter to reduce cold stimulation and improve the sleeping environment in disaster evacuation shelters. METHODS: Sixteen healthy male participants in Hiroshima City underwent 2 experimental conditions in January and December 2023: night-time sleep in winter with and without a sleeping bag-shaped aluminum sheets. Sleep-wake rhythm during night-time sleep (discriminant analysis method), subjective sleep soundness, mood state profile, heart rate, blood pressure, and cardiac autonomic nervous system modulation were measured. Wilcoxon's signed-rank sum test, Friedman's test, and paired RESULTS: Thermal sensation of warmth and subjective sleep soundness were significantly greater with than without the aluminum sheets. Total sleep time and sleep efficiency were also significantly greater, whereas the frequency and duration of wakefulness after sleep onset were significantly less. Total mood disturbance, fatigue-inertia, and vivid-activity were significantly different between the control, aluminum sheets, and home conditions. Physiological parameters did not differ significantly. CONCLUSIONS: These data suggest that using sleeping bag-shaped aluminum sheets in disaster evacuation shelters in winter could be effective in improving sleep-wake rhythms and subjective sleep soundness, although negative emotions were not improved.