title: Heat waves and cause-specific mortality at all ages.
abstract: BACKGROUND
  Mortality has been shown to increase with extremely hot ambient temperatures. Details on the specific cause of mortality can be useful for improving preventive policies. Infants are often identified as a population that is vulnerable to extreme heat conditions; however, information on heat and infant mortality is scarce, with no studies reporting on cause-specific mortality.
  
  
  METHODS
  The study includes all deaths in the Catalonia region of Spain during the warm seasons of 1983-2006 (503,389 deaths). We used the case-crossover design to evaluate the association between the occurrence of extremely hot days (days with maximum temperature above the 95th percentile) and mortality. Total mortality and infant mortality were stratified into 66 and 8 causes of death, respectively.
  
  
  RESULTS
  Three consecutive hot days increased total daily mortality by 19%. We calculated that 1.6% of all deaths were attributable to heat. About 40% of attributable deaths did not occur during heat-wave periods. The causes of death that were increased included cardiovascular and respiratory diseases, mental and nervous system disorders, infectious and digestive system diseases, diabetes, and some external causes such as suicide. In infants, the effect of heat was observed on the same day and was detected only for conditions originating in the perinatal period (relative risk = 1.53 [95% confidence interval = 1.16-2.02]). Within the perinatal causes, cardiovascular, respiratory, digestive system, and hemorrhagic and hematologic disorders were the causes of death with stronger effects.
  
  
  CONCLUSIONS
  Heat contributes to an increase in mortality from several causes. In infants, the first week of life is the most critical window of vulnerability.
authors.affiliation: Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain. xbasagana@creal.cat
authors.forename: Xavier
authors.initials: X
authors.lastname: Basagaña
authors.forename: Claudio
authors.initials: C
authors.lastname: Sartini
authors.forename: Jose
authors.initials: J
authors.lastname: Barrera-Gómez
authors.forename: Payam
authors.initials: P
authors.lastname: Dadvand
authors.forename: Jordi
authors.initials: J
authors.lastname: Cunillera
authors.forename: Bart
authors.initials: B
authors.lastname: Ostro
authors.forename: Jordi
authors.initials: J
authors.lastname: Sunyer
authors.forename: Mercedes
authors.initials: M
authors.lastname: Medina-Ramón
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D002648:Child; D002675:Child, Preschool; D004190:Disasters / Q000706:statistics & numerical data*; D005260:Female; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D006813:Humidity; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009026:Mortality; D012306:Risk; D012737:Sex Factors; D013030:Spain / Q000453:epidemiology; D055815:Young Adult