Gary Garcia-Molina, PhD, Sr. Principal Scientist at Sleep Number and honorary research fellow at the University of Wisconsin-Madison

Gary Garcia-Molina, PhD

Sleep Number Corporation presented new data at 

showing that personalized bed temperature, a feature of its ClimateSeries smart beds, can improve sleep quality and well-being. Across 3 studies, this approach helped users fall asleep faster and stay asleep longer.

One observational study of > 9,000 sleep sessions found that for women experiencing menopause symptoms, cooling the bed most of the night, followed by gentle warming before waking, significantly reduced hot flashes and sleep disruptions.

Another analysis of 2.2 million sleep sessions revealed gender differences: women benefited most from starting with low heat followed by cooling, while both men and women slept better when bed temperature aligned with natural body rhythms—warm at bedtime, cooler overnight.

A third study showed that warming the bed at the start of the night helped people fall asleep faster and enter deep sleep sooner, reducing time awake and increasing 

In this Q&A, Gary Garcia-Molina, PhD, Sr. Principal Scientist at Sleep Number and honorary research fellow at the University of Wisconsin-Madison, discussed the motivation behind studying bed temperature control, gender and age-related differences in thermoregulation, and the potential role of temperature interventions in behavioral sleep medicine.

 What prompted your team to investigate the role of bed temperature control in sleep quality?

 Several lines of evidence show that temperature and sleep are closely interrelated, with a causal relationship between core body and skin temperature changes, and sleep initiation, sleep maintenance and overall sleep quality. This motivated us to test the hypothesis that optimizing in-bed microclimate temperature could meaningfully improve sleep.

How did you design the temperature programs across the four nightly sleep segments, and what guided those choices?

Our temperature programs were developed in collaboration with Northwestern University, under the guidance of Dr. Phyllis Zee (an expert in sleep, circadian science, and temperature), with input from Dr. Eus van Someren (an expert in thermoregulation and sleep). The study had 2 phases: a controlled, in-lab environment at Northwestern’s sleep lab and an at-home study using research-grade sensors.

The data from those sensors and the smart bed estimated sleep/wake metrics were used in our analyses. We also analyzed data from approximately 80,000 Sleep Number customers who use smart beds daily. These data sources enabled us to optimize and personalize temperature programs for different segments of the night, aiming to maximize sleep quality across diverse demographic segments.

What were the most significant differences in sleep quality improvements between men and women in your findings?

For women, initiating sleep with low heating and transitioning to medium or low cooling yielded the largest improvement in sleep quality, about 13.2%. Men also benefited from similar transitions, though the effect was slightly smaller at around 7.2%.

These differences may reflect physiological variations in thermoregulation, including hormonal influences and differences in peripheral blood flow. Sleep quality was measured using a compound metric incorporating sleep duration, sleep depth, and low sleep fragmentation.

Why might women respond more positively to the heating-then-cooling pattern compared to men?

Women may respond more positively to the heating-then-cooling pattern due to differences in thermoregulatory physiology, including hormonal fluctuations (such as those during the menstrual cycle or menopause) and a greater tendency for increased peripheral blood flow (which may increase sensitivity to subtle changes in skin temperature, such as the one promoted by the Sleep Number smart bed). These factors can make women more sensitive to temperature changes during sleep initiation and maintenance, enhancing the benefits of targeted temperature modulation.

Were there any surprising findings regarding the timing or intensity of heating and cooling that clinicians should know about?

One notable finding is that women in the menopausal transition benefit from temperature programs that differ from those optimal for the general population. Indeed, women in the menopause transition benefit from cooling in most of the sleep session, followed by low heating in the period before waking up.

Menopausal women often experience more frequent awakenings and vasomotor symptoms (such as night sweats), making tailored temperature interventions particularly important for improving their sleep continuity and quality. 

How might aging or hormonal shifts affect thermoregulation and responsiveness to bed temperature control?

Aging and hormonal changes (such as those occurring during menopause) can alter the body’s ability to regulate temperature.

Also, older adults may have reduced peripheral blood flow and impaired vasodilation, making them more sensitive to ambient temperature. This can lead to increased sleep fragmentation and reduced sleep quality unless temperature is carefully managed. 

How might these findings inform temperature-based interventions for patients with insomnia or other sleep disorders?

Our findings suggest that temperature-based interventions, such as those enabled by smart beds, can be effective for patients with insomnia or other sleep disorders.

Insomnia: Heating at sleep onset, followed by cooling, accelerates sleep initiation and deep sleep (via elevated delta-beta ratios), reducing sleep latency and fragmentation.

Sleep-Disordered Breathing (SDB): Recent evidence suggests that higher ambient temperatures during sleep are linked to worsened apnea symptoms. Smart beds can counter the effect of higher ambient temperature by cooling down the microenvironment in bed.

Chronic Pain: Targeted warming may alleviate musculoskeletal discomfort by improving peripheral blood flow and reducing pain-related microarousals.

Do you see potential for integrating smart bed temperature programs into behavioral sleep medicine or cognitive behavioral therapy for insomnia (CBT-I)?

Yes. Smart bed temperature programs can be integrated into behavioral sleep medicine and CBT-I as a non-pharmacological, evidence-based tool to improve sleep initiation and maintenance. Importantly, smart beds also provide objective metrics such as bed occupancy and time-in-bed, key cornerstones for CBT-I, which relies on accurate sleep restriction and stimulus control protocols. These metrics help clinicians and patients monitor adherence to prescribed sleep schedules and optimize treatment plans. By combining personalized temperature optimization with real-time feedback on time-in-bed and bed occupancy, smart beds offer a comprehensive platform to enhance the effectiveness and personalization of CBT-I interventions.

What are the next steps for your team in exploring gender-specific thermoregulation and sleep?

Our next steps involve leveraging the unique capabilities of our smart bed platform, which continuously collects large-scale, real-world sleep and temperature data across diverse demographic groups and seasons. This ongoing data collection enables us to investigate season-dependent temperature optimization, ensuring that our recommendations are responsive to environmental changes throughout the year. Additionally, through our science panel, we can gather rich contextual information from participating customers (including health status, lifestyle factors, and sleep-related symptoms), which allows us to discover subtle associations between temperature interventions and a variety of conditions, such as menopause, sleep-disordered breathing, insomnia, and chronic pain.

Is there anything else you would like to highlight about these findings?

By integrating contextual insights with objective sleep and temperature metrics, we are essentially conducting one of the largest and most longitudinal sleep studies to date. This approach provides unique opportunities to uncover patterns and causal relationships that would be difficult or impossible to detect in smaller, short-term studies. There is still much to learn about the complex interplay between temperature and sleep, and our platform’s scale and depth of data will be instrumental in advancing personalized, evidence-based temperature interventions for sleep health across the lifespan.

Sleep Number® Smart Bed Research from Over 9,100 Sleep Sessions Shows How Built-In Temperature Programs Improve Sleep, Especially for Women. BusinessWire. June 10, 2025. 

https://www.businesswire.com/news/home/20250609952904/en/Sleep-Number-Smart-Bed-Research-from-Over-9100-Sleep-Sessions-Shows-How-Built-In-Temperature-Programs-Improve-Sleep-Especially-for-Women

Articles

Sleep Number Corporation's research presented at SLEEP 2025 highlights the impact of personalized bed temperature on sleep quality and well-being. Studies show that temperature adjustments can help users fall asleep faster and stay asleep longer. Women, particularly those experiencing menopause, benefit significantly from specific temperature patterns. Gender differences in thermoregulation were observed, with women responding better to heating-then-cooling patterns. The research suggests that smart bed temperature programs could be integrated into behavioral sleep medicine and cognitive behavioral therapy for insomnia, offering a non-pharmacological approach to improving sleep quality.

Sleep Number studies presented at SLEEP 2025 show that heating and cooling patterns improve sleep quality, especially for women experiencing menopause.
