Modeling temperature effects on mortality: multiple segmented relationships with common break points

We present a model for estimation of temperature effects on mortality that is able to capture jointly the typical features of every temperature–death relationship, that is, nonlinearity and delayed effect of cold and heat over a few days. Using a segmented approximation along with a doubly penalized spline-based distributed lag parameterization, estimates and relevant standard errors of the cold- and heat-related risks and the heat tolerance are provided. The model is applied to data from Milano, Italy.