When talking about health everyone mentions exercise, diet and lifestyle. There is a wealth of advice for everything from what to eat, to which heart rates are advisable for maximum impact. Increasingly, however, health experts are beginning to realise that while we may not know what sleep does exactly, it is absolutely critical for maintaining maximum physical and mental health. Getting a good night’s sleep is now thought to be almost as critical as the foods you are eating and yet it seems like not nearly as much effort has been put in, to discovering exactly how to do that.
Now a recent investigation has shed light on the ideal sleeping conditions, indicating that the optimal bedroom temperature falls between 20 to 25 degrees Celsius. These findings have emphasised the pivotal role of ambient temperature in the initiation and maintenance of sleep and pointed to an increasing, and as yet, unconsidered problem in a world stricken by global warming.
Dr Sudha Tallavajhula, a sleep neurologist at UTHealth Houston and TIRR Memorial Hermann, expanded upon the significance of temperature in the sleep process, stating, “For the initiation of sleep, low ambient light and temperature send signals to the body that it’s time to secrete neurotransmitters that facilitate sleep.” During our slumber, our bodies oscillate through different temperature-regulation phases. Notably, during REM sleep, our ability to control temperature diminishes, rendering us vulnerable to external factors.
High room temperatures disrupt this delicate equilibrium, hindering the body’s adjustment mechanisms and leading to people waking frequently during the night. The study, which involved participants wearing sleep monitors and environmental sensors, encompassed data from 50 adults over 11,000 nights of sleep and environmental observations. The results exposed a drop in sleep efficiency ranging from 5 to 10% as the temperature climbed from 25 to 30 degrees Celsius.
Discussing the findings, Amir Baniassadi, the lead researcher from the Hinda and Arthur Marcus Institute for Aging Research at Hebrew SeniorLife and Harvard Medical School, pointed out the correlation with these results and climate change, “Both climate change and urban-induced warming, also known as the urban heat island effect, can significantly elevate nighttime temperatures. Consequently, cities experiencing higher temperatures are likely to witness a decline in sleep quality and ultimately health”.
This predicament disproportionately affects those who lack the financial means to cool their homes and reside in dwellings prone to overheating. People with lower socioeconomic status tend to inhabit densely populated areas with limited green spaces, where the urban heat island effect is more pronounced. Furthermore, they often have limited access to healthcare to address the health consequences of disrupted and inadequate sleep.
As Dr Tallavajhula points out, “Several studies have now looked at the effect of climate change on sleep quality, many in adults and also some in children.” In general, age-related changes in sleep depth and duration are expected. However, older adults with underlying medical conditions, mental health issues, sleep disorders, or those taking specific medications are particularly vulnerable to environmental disruptions.
To address these challenges, Amir Baniassadi emphasises the need to prioritise the most at-risk populations in research efforts and develop strategies to assist them in adapting to a changing climate. Two key groups are of particular interest: older adults who cannot afford to cool their homes and those who struggle with limited mobility or cognitive decline. The study’s next steps involve exploring automated temperature regulation systems tailored to these individuals’ specific needs.
For those looking to improve their sleep quality, Dr. Tallavajhula offers some valuable advice:
- Maintain a regular sleep schedule, aligning your body’s internal clock with consistent sleep and wake times.
- Keep the bedroom dimly lit and cool to promote a favourable sleep environment.
- If you struggle to fall asleep, consider refraining from daytime naps.
- Wind down at the end of the day with relaxing activities, avoiding stimulating tasks that can interfere with sleep initiation.
- If all personal efforts to improve sleep prove ineffective, consult a sleep medicine specialist for expert guidance and potential solutions.
