Bedroom Temperature Linked to Heart Health Risk in Older Adults, Study Finds

The temperature of your bedroom at night could have significant implications for heart health, particularly for older adults, according to new research from Australia.

A study led by Dr. Fergus O’Connor from Griffith University in Queensland found that sleeping in rooms warmer than 75 degrees Fahrenheit may impair cardiovascular recovery during sleep—a crucial time when the body should be repairing itself from daily stresses.

“When the human body is exposed to heat, its reaction is to work harder to try and circulate blood to the skin surface for cooling,” O’Connor explained. “However, when the heart works harder and for longer, it creates stress and limits our capacity to recover from the previous day’s heat exposure.”

The research team followed 47 adults with an average age of 72 living in southeast Queensland throughout an entire Australian summer, from December to March. Unlike many sleep studies conducted in clinical settings, this was a “free-living” study where participants maintained their normal daily routines and sleep schedules.

Each participant wore a high-tech fitness tracker to monitor heart rate between 9 p.m. and 7 a.m., while sensors placed directly in their bedrooms recorded temperatures. The study monitored over 14,000 nighttime hours of sleep in total, providing researchers with robust data on how ambient temperature affects heart function during rest.

The results revealed a concerning pattern. When bedroom temperatures exceeded 75 degrees Fahrenheit, the odds of experiencing a “clinically relevant” drop in heart recovery increased by 40% at temperatures between 75-79°F. This risk doubled when temperatures reached 79-82°F and nearly tripled in bedrooms warmer than 82°F.

“For individuals aged 65 years and over, maintaining overnight bedroom temperatures at 24°C (75.2°F) reduced the likelihood of experiencing heightened stress responses during sleep,” O’Connor noted.

These findings have particular relevance as climate change drives more frequent and intense heatwaves globally. While many regions provide guidance for maximum daytime indoor temperatures, O’Connor pointed out a significant gap in public health recommendations: there are currently no equivalent guidelines for nighttime conditions, when many vulnerable people spend hours in enclosed spaces.

The cardiovascular system’s ability to recover during sleep is essential for overall heart health. When this recovery is impaired night after night due to elevated temperatures, it could potentially contribute to long-term cardiovascular problems, especially in older adults who may already have underlying health conditions.

While the study shows a strong correlation between bedroom heat and heart stress, the researchers acknowledge limitations in their work. The observational design means it cannot definitively prove heat as the sole cause of the observed effects. Additionally, the study’s focus on older Australians may limit its applicability to other populations or geographic regions with different climate patterns.

Another limitation involves the technology used. While modern fitness trackers provide valuable continuous monitoring capabilities, they don’t offer the precision of medical-grade electrocardiograms (ECGs) used in clinical settings.

Nevertheless, the research adds to growing evidence that environmental factors, including ambient temperature, play an important role in cardiovascular health. Previous studies have linked heat exposure to increased risk of heart attacks, strokes, and other cardiovascular events, particularly during heatwaves.

For older adults concerned about heart health, these findings suggest that maintaining cooler bedroom temperatures—ideally below 75°F—may be a simple yet effective preventive measure. This could involve using air conditioning, fans, or other cooling strategies, especially during summer months or in warmer climates.

The study was published in the peer-reviewed journal BMC Medicine, adding credibility to its findings and highlighting the importance of considering environmental factors in heart health management strategies.