Abstract:
Climate change has resulted in rising temperature trends which have been associated with
changes in temperature extremes globally. Attendees of Conference of the Parties (COP) 21 agreed to
strive to limit the rise in global average temperatures to below 2 C compared to industrial conditions,
the target being 1.5 C. However, current research suggests that the African region will be subjected
to more intense heat extremes over a shorter time period, with projections predicting increases of
4–6 C for the period 2071–2100, in annual average maximum temperatures for southern Africa.
Increased temperatures may exacerbate existing chronic ill health conditions such as cardiovascular
disease, respiratory disease, cerebrovascular disease, and diabetes-related conditions. Exposure to
extreme temperatures has also been associated with mortality. This study aimed to consider the
relationship between temperatures in indoor and outdoor environments in a rural residential setting
in a current climate and warmer predicted future climate. Temperature and humidity measurements
were collected hourly in 406 homes in summer and spring and at two-hour intervals in 98 homes
in winter. Ambient temperature, humidity and windspeed were obtained from the nearest weather
station. Regression models were used to identify predictors of indoor apparent temperature (AT)
and to estimate future indoor AT using projected ambient temperatures. Ambient temperatures
will increase by a mean of 4.6 C for the period 2088–2099. Warming in winter was projected to be
greater than warming in summer and spring. The number of days during which indoor AT will be
categorized as potentially harmful will increase in the future. Understanding current and future
heat-related health effects is key in developing an effective surveillance system. The observations
of this study can be used to inform the development and implementation of policies and practices
around heat and health especially in rural areas of South Africa.
