Temperature influence on circadian rhythms

Scientific research is increasingly examining the role of ambient temperature in regulating the human circadian rhythm and sleep quality. While light has traditionally been considered the primary regulator of the biological clock, new studies suggest that temperature fluctuations may be as significant.

Research indicates that the body’s core temperature naturally drops by approximately one degree Celsius during the night to prepare for sleep. Controlled experiments have shown that participants sleeping in environments with natural temperature fluctuations—where temperatures decrease during the evening and rise toward the morning—exhibit higher melatonin levels and report feeling more rested than those in constant temperature environments.

Anthropological observations of indigenous communities, including the Tsimane, Hadza, and San, have contributed to this field. Observations by anthropologist Gandhi Yetish suggest that sleep schedules in these groups do not always align strictly with light and dark cycles, further supporting the investigation into temperature as a key biological regulator.