Getting a good night’s sleep becomes more important as people grow older. Sleep helps the body recover, repair itself, and prepare for the next day.
However, many older adults struggle with sleep, especially during hot summer nights. Now, new research from Australia suggests that something as simple as adjusting the bedroom temperature could make a meaningful difference.
Researchers at Griffith University have found that keeping the bedroom at around 24°C during the night may help reduce stress levels in older adults while they sleep. The findings offer new insight into how temperature affects the body during sleep and may help people stay healthier as temperatures continue to rise around the world.
The study was led by Dr. Fergus O’Connor from Griffith University’s School of Allied Health, Sport and Social Work and was published in the journal BMC Medicine.
The researchers focused on adults aged 65 years and older. As people age, their bodies become less efficient at regulating temperature. Older adults may find it harder to cool down when the weather is hot, making them more vulnerable to heat-related health problems.
This can be especially concerning during heatwaves and warm nights, which are becoming more common because of climate change.
Scientists have long known that excessive heat can interfere with sleep. However, most previous studies were conducted in laboratory settings. This new research is important because it examined people in their normal home environments over an entire summer, providing a clearer picture of what happens in real life.
To carry out the study, participants wore fitness trackers on their wrists while sleeping. These devices continuously measured heart rate and indicators of physical stress. At the same time, sensors placed inside their bedrooms recorded temperature conditions throughout the night.
By comparing the health data with bedroom temperatures, the researchers discovered a clear pattern. When bedroom temperatures stayed around 24°C, participants showed lower signs of stress during sleep. As bedroom temperatures increased above this level, stress responses became more noticeable.
According to Dr. O’Connor, this effect is linked to how the body tries to stay cool. When temperatures rise, the body works harder to remove excess heat. One of the main ways it does this is by increasing blood flow to the skin. To make that happen, the heart must pump more blood, causing heart rate to increase.
While this cooling process is important for survival, it places additional demands on the cardiovascular system. If the heart continues working harder throughout the night, the body may not get the chance to fully recover from the heat experienced during the day. This ongoing strain can increase physical stress and potentially affect overall health.
The findings suggest that sleep is not just a period of rest but also an important recovery time for the body’s cooling systems. When bedroom temperatures are too high, that recovery process may be interrupted. As a result, people may wake up feeling less refreshed and may experience greater stress on their bodies over time.
The study is particularly relevant because climate change is increasing the number of hot nights in many parts of the world. While people often focus on high daytime temperatures, warm nights can also have serious health consequences. If the body does not cool down properly during sleep, the risk of heat-related illness may rise.
Researchers note that older adults are among the groups most vulnerable to these effects. Many older people already have health conditions affecting the heart, blood vessels, or breathing. Additional stress caused by hot sleeping environments may place further pressure on these systems.
In Australia, health guidelines currently recommend keeping indoor temperatures below 26°C during the day to help protect health. However, there are no official recommendations for bedroom temperatures at night. The new findings suggest that nighttime temperature guidelines may be worth considering, especially for older adults and other vulnerable groups.
The results also offer practical advice that many people can apply immediately. Using fans, air conditioning, improved ventilation, blackout curtains, or lighter bedding may help keep bedrooms closer to the recommended temperature. Even small reductions in bedroom heat may improve comfort and support healthier sleep.
Although more research is needed to understand the long-term effects, this study provides strong real-world evidence that bedroom temperature matters. Maintaining a cooler sleeping environment may help older adults reduce stress on their bodies, support heart health, improve sleep quality, and recover more effectively from hot weather.
As global temperatures continue to rise, simple strategies such as keeping bedrooms around 24°C may become an increasingly important part of staying healthy and sleeping well.
The study was published in the journal BMC Medicine.
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