Lack of Thermal Comfort Is a Matter of Life and Death: A Systematic Review for Older People

Thermal comfort is not a luxury; rather, a lack of it is a matter of life and death, particularly for vulnerable people, such as older people. This work systematically reviews and analyses the thermal comfort of older people and their health and mortality as it relates to exposure to extreme temperatures, and suggests acceptable thermal conditions and the related energy use of buildings. A total of 69 out of 198 papers were found on older people and these were analysed in detail. This was followed by an analysis of the UN and UK governments’ open access data. This work highlights the disparity regarding the definition of age for older people and encourages the use of the term older people, rather than elderly, which can be an offensive piece of terminology. The UK findings suggest a significant relationship between cold (below 5 °C) outdoor air temperatures and mortality in older people, particularly for those who are over 85 years old. In the UK, thermal conditions can lead to up to 175 deaths per degree temperature change up to two weeks after a cold spell or an overly hot period. The indoor comfort temperature of older people varies between 22.5 and 27 °C in natural ventilation mode. However, some studies found 18 °C to be comfortable in winter time, a finding which could lead to a significant energy saving in relation to space heating. Current gaps in and the recommended future direction of research include topics such as gender differences in terms of thermal comfort and during menopause; thermal comfort conditions, adaptive behaviours and naturally ventilated buildings; thermal conditions when sleeping and energy use as it relates to space heating or cooling for older people. © 2025 by the authors.