The Centre for Sustainable Energy (CSE) has shared a fan-free hack to keep bedrooms cool during hot weather: using a damp bed sheet as a duvet. Katey Bell, part of the energy advice team at CSE, recommends running a bedsheet under the tap, wringing it out, and using it as a duvet on sweltering nights. 'Nothing I've found works better for getting a good night's sleep in the heat,' she said.
How to use a damp sheet effectively
To avoid a wet mattress, wring the sheet out as much as possible. Alternatively, put a wet sheet or duvet cover on a spin cycle in the washing machine to make it damp but not wet. For bottom sheets, place a waterproof mattress protector between the sheet and the bed to prevent moisture damage.
Other fan-free cooling tips
Bell also suggests hanging a wet sheet in front of an open window. During the day, sunlight heats the air near windows, which gets trapped inside. A damp sheet absorbs heat from the air before it enters the room, lowering the temperature. Once the sheet dries, lightly dampen it again to maintain a cooler bedroom even in extreme heat.
Many people avoid fans due to noise, dust circulation, or higher electricity bills. This simple method uses evaporation to cool the room without any energy consumption.
