Influence of local factors in the relationship between mortality and heat waves: Castile-La Mancha (1975-2003)

► One of the principal consequences of the climate change is the increase in heat waves. ► We examined the effect of heat waves on daily non-accidental-cause mortality in the Castile-La Mancha Region (Spain). ► Mortality increased when temperatures exceeded the designated Castile-La Mancha provincial thresholds and varies by province. ► The longest heat waves were associated with daily mortality and those at the end of summer cause the lowest mortality. ► The percentile at which the heat-wave threshold temperature occurs is inversely proportional to each province's old-age index.