No escape from the heat? Bedroom temperatures during England’s hottest summer

Numerous monitoring studies have demonstrated overheating of bedrooms in English homes during summer. Elevated bedroom temperatures can degrade sleep quality and impinge on health and well-being. This paper examines Public Health England’s advice to ‘move into a cooler room, especially for sleeping’ in hot conditions. Temperatures were monitored in 33 dwellings across the English Midlands between 1 May and 30 August 2018: the joint hottest English summer on record. The bedroom temperatures were analysed using the recommended CIBSE criterion that there should be no more than 1% of annual occupied hours over 26°C; adaptive comfort criteria are deemed inappropriate for sleeping persons. In half of the main bedrooms, temperatures exceeded 24°C for more than a third of sleeping hours. The CIBSE overheating criterion wasexceeded in 78% of master bedrooms. Even if everybody in a household slept in the coolest bedroom, 70% would still experience overheating. Assessing the living room as a bedroom led to a substantial reduction in homes classed as overheating. It is concluded that, whilst public health advice to seek cooler spaces during hot weather is well founded, such ‘safe havens’ for sleeping may exist only for a minority of English households. Further work is, however, needed.