Why sleeping cool matters more than you think

The article highlights the critical role of maintaining a cool sleeping environment for improving sleep quality, based on insights from Lara Smith, founder of Lusomé and expert in textiles and thermoregulation. Central to the discussion is a Harvard-led clinical trial involving 64 participants who slept in their own beds, generating nearly 2,700 nights of real-world data. The study found that using a sleep surface designed to regulate temperature resulted in an average increase of 26 minutes of sleep per night—a clinically meaningful improvement, especially for individuals with insomnia. Smith emphasizes that even small gains in sleep duration can compound over time to significantly benefit health. Physiologically, the body needs to cool down to initiate and maintain restorative sleep, as overheating delays sleep onset and reduces deep and REM sleep by activating the sympathetic nervous system. The microclimate around the body, including bedding and sleep surfaces, often matters more than ambient room temperature. This issue is particularly acute for women undergoing perimenopause and menopause, whose declining estrogen levels