The key for people to sleep could be how hot or cold a room is. Researchers say the best quality sleep is in a room between 20-25º Celsius. The researchers asked 50 people aged 65 and older to wear a sleep monitor for 18 months. The people's sleep worsened when their room temperature was not between 20-25ºC. Researchers say 20ºC is the best temperature. They said sleep seems easier and is often deeper in a cooler environment.

Temperature could be as bad for sleep as pain or drinking alcohol. Researchers found a 5-10 per cent drop in sleep quality when it was too warm or too cool. Poor sleep can lead to health problems, like mood swings and stress. Other problems include a risk of getting diabetes and heart disease. The researchers said people should create, "a more comfortable home environment" to sleep well. They also said climate change could change our sleep.