Mean radiant temperature - A predictor of heat related mortality

Health studies have repeatedly used air temperature (T-a), sometimes adjusted for humidity, when analyzing the impact of weather on mortality. The aim of this study is to highlight the importance of mean radiant temperature (T-mrt) and its impact on heat related mortality. T-mrt is an essential meteorological parameter that influences the thermal comfort (heat load) of humans. It is useful when assessing the impact of weather, especially heat, on people's health. T-mrt is directly influenced by urban geometry and surface material, which also makes it a good measure to identify urban hot spots. The performance of models using T-a and Tmrt for daily mortality is compared for Stockholm County, Sweden. It is demonstrated that T-mrt models fit heat related mortality better than T-a models, which implies that health studies should consider using T-mrt rather than T-a. The use of T-mrt models allows us to determine more accurate thresholds for increased risks of heat related mortality, and thus to better identify adverse weather conditions and heat prone urban geometries. Such information is needed to implement heat-warning systems and mitigate harmful effects of heat stress. (C) 2014 Elsevier B.V. All rights reserved.