New research indicates that maintaining a room temperature of 24 degrees Celsius or below can significantly reduce sleep stress for older Australians. This finding is crucial for improving the well-being of a vulnerable population, especially during warmer months. The study, conducted by Griffith University researchers and published in BMC Medicine, highlights a direct correlation between elevated overnight bedroom temperatures and increased physiological stress responses in individuals aged 65 and over.
Participants in the study were equipped with health monitoring devices to track their physiological status throughout the summer period of December 2024 to March 2025. The data collected provided valuable insights into how sleeping environments impact the body. Fergus O’Connor, one of the researchers, explained that as overnight bedroom temperatures rose, so did the participants’ stress responses, leading to diminished recovery.
Featured snippet paragraph: The answer is that keeping room temperatures at 24 degrees Celsius or below can reduce sleep stress in older adults by decreasing heart rate variability and physiological stress responses, allowing for better recovery during sleep.
When temperatures exceeded 24 degrees Celsius, particularly reaching 28 or 30 degrees Celsius, participants often found themselves in a state resembling the body’s “fight or flight” response while sleeping. This physiological demand to dissipate heat prevents the body from achieving true rest and recovery. While there wasn’t a single temperature that immediately signaled danger, the study observed a clear trend of worsening outcomes as temperatures climbed.
Senior researcher Georgia Chaseling from the University of Sydney confirmed that the study reinforces existing knowledge about the impact of hot sleeping environments on heart rate. “We already know a little bit that when there are hotter nights, they’re linked to changes in heart rate patterns and heart rate variabilities,” she stated.
Chaseling also noted that while the study shows an association between hot weather and changes in heart rate variability, it doesn’t definitively prove causation. She suggested that future research should aim to pinpoint the precise relationship by controlling for daily activities and examining a wider range of climates and participant groups.
The research emerges at a time when many parts of Australia are experiencing severe heatwaves, with temperatures frequently exceeding 40 degrees Celsius. Dr. O’Connor emphasized that while increased risk doesn’t always lead to immediate negative health outcomes, the cumulative effect of prolonged periods of sleeping in high temperatures can be detrimental.
He further elaborated that during extended heatwaves, hospitalizations tend to rise. When individuals are unable to achieve adequate overnight recovery due to heat, it is highly probable that this plays a significant role in the increased hospital admissions observed during such periods. The study’s findings became more pronounced for negative effects on HRV and heart rate at temperatures of 26 degrees Celsius and above.
For those without air conditioning during heatwaves, Dr. Chaseling offered practical advice for regulating body temperature. Using fans at night is recommended, particularly when the ambient air temperature is below 35 degrees Celsius, which is common for nighttime conditions.
Other cooling strategies include using spray bottles or damp towels to moisten the skin before sleep and taking a cold shower. These methods can help individuals fall asleep more easily and maintain a cooler body temperature throughout the night.
Despite the World Health Organization providing guidelines for maximum daytime indoor temperatures, there is a lack of similar recommendations for nighttime temperatures. Dr. O’Connor sees this study as a foundational step towards establishing objective evidence for setting maximum nighttime indoor temperature guidelines.
These guidelines could aid in reducing stress and facilitating recovery from daily heat exposure. He stressed the importance of expanding this research to encompass more diverse populations and geographical areas with varying climatic conditions. This work is a significant stride towards developing comprehensive indoor temperature guidelines that address both daytime and nighttime conditions.
This exploration into sleep temperature and its effects is vital for public health, especially as climate change continues to influence weather patterns and increase the frequency of extreme heat events. Understanding and implementing these findings can lead to better sleep quality and overall health for older adults.
Keeping room temperature at 24 degrees Celsius or below is a key strategy for older Australians to mitigate sleep stress and improve their physiological recovery. This research provides a solid evidence base for future public health recommendations and personal adjustments to sleeping environments.
