Evolution of the threshold temperature definition of a heat wave vs. evolution of the minimum mortality temperature: a case study in Spain during the 1983–2018 period

Abstract Background An area of current study concerns analysis the possible adaptation population to heat, based on temporal evolution minimum mortality temperature (MMT). It is important know how threshold temperatures (Tthreshold) due these provide basis for activation public health prevention plans against high temperatures. The objective this was analyze produced in different Spanish regions during 1983–2018 period and compare with MMT. dependent variable used raw rate daily natural causes ICD X: (A00-R99) considered period. independent maximum (Tmax) summer months registered reference observatory each region. Threshold values were determined using dispersion diagrams (annual) prewhitened series Tmax. Later, linear fit models carried out between Tthreshold throughout period, which permitted detecting annual change Tthreshold. Results results obtained show that, average, has increased at a 0.57 ºC/decade Spain, while Tmax have 0.41 ºC/decade, suggesting heat. This presents geographic heterogeneity. Also, similar what detected Conclusions both measures can be as indicators variation, probably related sociodemographic economic factors, that should studied local level.