For countless individuals grappling with the vexing issue of restless and insufficient sleep, particularly during sweltering nights, a pivotal question arises: What temperature is conducive to a tranquil slumber?
Novel research, conducted on a cohort of 50 volunteers aged over 60 and situated in Boston, USA, has uncovered a groundbreaking revelation – the optimal temperature range that facilitates the most rejuvenating sleep for older adults hovers between 20 to 25 °C (68 to 77 °F).
As ambient temperatures ascend from 25 °C to 30 °C, the study’s participants experienced a pronounced drop in sleep efficiency. This metric, indicative of the time spent asleep after retiring to bed, plummeted by as much as 10 percent under these elevated conditions.
This decline bears substantial significance, as prior studies have unveiled that a 10 percent decrease in sleep efficiency can precipitate impaired brain function, heightened stress, anxiety, and fatigue, alongside disruptions in the body’s regulation of blood sugar levels the following day.
Given the escalating temperatures accompanying global warming, the study’s findings reinforce the imperative of enhancing the thermal comfort within residences, particularly in environments such as aged care homes and public housing. Efforts to address this challenge span beyond conventional air conditioning solutions, extending to innovative avenues such as reflective paints and advanced building materials.
Amir Baniassadi, an engineer and health researcher at Harvard Medical School who spearheaded the research, underscores the significance of considering sleep as a foundational element when assessing the broader ramifications of climate change. “As we grapple with the broader implications of climate change, we must not overlook its potential impact on something as fundamental as sleep,” Baniassadi asserts.
The repercussions of inadequate sleep on both physical and mental well-being are well-documented, shaping not only cognitive performance but also interpersonal relationships. Longitudinal studies and historical data reveal that past temperature elevations have likely disrupted sleep patterns in profound ways, with projections pointing towards a future of further sleep disturbances due to continued warming.
By the year 2099, heightened temperatures could erode approximately 50 hours of sleep per individual annually, bearing significant implications for the elderly population, who are particularly susceptible to heat stress both day and night.
Distinguished by its unique approach, this study diverges from the controlled environments of conventional sleep research, tracking individuals’ sleep patterns and ambient temperatures within their own domiciles. The participants, aged 65 and above, had indoor air temperature and humidity sensors installed in their bedrooms, while wearing a ring-like device that captured data on sleep, skin temperature, heart rate, and movement.
Harnessing a trove of nearly 11,000 person-nights of sleep and environmental data, the study unveils the pivotal role of temperature. While the optimal range lies between 20 and 25 °C, Baniassadi underscores the individualized nature of this phenomenon, asserting that each person may possess their own optimal temperature range that might even evolve over time.
For individuals striving to optimize their sleep environment, subtle modifications such as improved airflow and lightweight sleep attire can yield incremental benefits. Yet, the potential for more significant improvements lies in augmenting the thermal comfort of the built environment, even though it poses a greater challenge, both technically and economically.
