Cooling mattress toppers an effective and low-energy way to improve sleep in hot bedrooms, study finds

Rising UK summer temperatures—1.25°C higher on average since 2014—have made overheated bedrooms a growing problem, with 4.6 million English homes experiencing excessive heat during the 2018 summer. Traditional UK housing, designed for heat retention, struggles to cool efficiently, leaving many without practical solutions like air conditioning due to cost, energy concerns, or installation challenges. Loughborough University researchers, led by PhD candidate Jaydeep Bhadra and supervised by Dr Arash Beizaee and Dr Iuliana Hartescu, tested a cooling mattress topper as a low-energy alternative. The study involved 17 adults comparing three sleep conditions: their own homes under summer conditions, a controlled 30°C bedroom with standard bedding, and the same bedroom with the cooling topper. Sleep quality was measured using wrist devices and participant feedback. Results showed the topper improved thermal comfort, increasing total sleep time by 19 minutes and reducing time to fall asleep by 10 minutes in overheated conditions. Participants reported feeling more rested and comfortable. The findings, published in *Building and Environment*, suggest the topper could mitigate sleep disruption caused by hot nights without straining energy grids. Dr Beizaee noted that climate change and urbanization are worsening hot nights in the UK, making localized cooling solutions critical. While promising, further research will explore long-term effects, humidity, and air quality to refine building standards and public health guidance. The study highlights a scalable, energy-efficient method to address overheating in homes without relying on widespread air conditioning.