International Journal of Biometeorology

, Volume 57, Issue 1, pp 155–167 | Cite as

Excess mortality and morbidity during the July 2006 heat wave in Porto, Portugal

  • Ana Monteiro
  • Vânia Carvalho
  • Teresa Oliveira
  • Carlos Sousa
Original Paper


The purpose of this study was to understand the effects of the July 2006 heat wave through the use of the heat index, in mortality (all causes) and morbidity (all causes, respiratory and circulatory diseases) in general, and in people over 74 years and by gender, in Porto. In this paper, the Poisson generalized additive regression model was used to estimate the impact of apparent temperature (heat index) and daily mortality and morbidity during the July 2006 heat wave. Daily mortality, morbidity and heat index were correlated with lags of apparent temperature up to 7 days using Pearson correlation. For a 1°C increase in mean apparent temperature we observed a 2.7 % (95 % CI: 1.7–3.6 %) increase in mortality (all cause), a 1.7 % (95 % CI: 0.6–2.9 %) increase in respiratory morbidity, a 2.2 % (95 % CI: 0.4–4.1 %) increase in respiratory morbidity in women, a 5.4 % (95%CI: 1.1–6.6 %) increase in chronic obstructive pulmonary morbidity, and a 7.5 % (95 % CI: 1.3–14.1 %) increase in chronic obstructive pulmonary morbidity in women, for the entire population. For people ≥ 75 years, our results showed a 3.3 % increase (95 % CI: 1.7–5.0 %) in respiratory morbidity, a 2.7 % (95 % CI: 0.4–5.1 %) increase in respiratory morbidity in men, a 3.9 % (95 %CI: 1.6–6.3 %) increase in respiratory morbidity in women, a 7.0 % (95 % CI: 1.1–13.2 %) in chronic obstructive pulmonary disease, and a 9.0 % (95 % CI: 0.3–18.5 %) in chronic obstructive pulmonary disease in women. The use of heat index in a Mediterranean tempered climate enabled the identification of the effects of the July 2006 heat wave in mortality due to all causes and in respiratory morbidity of the general population, as well as in respiratory morbidity of individuals with more than 74 years of age.


Heat wave Heat index Mortality Respiratory disease Circulatory disease Air pollution 



We would like to thank Drª. Fátima Candoso (Health System Central Administration) and Dr. Fernando Lopes (São João Hospital) for support.

Competing interests

The authors declare that they have no competing interests.


  1. Almeida S, Casimiro E, Calheiros J (2010) Effects of apparent temperature on daily mortality in Lisbon and Porto, Portugal. Environ Health 9:12. doi: 10.1186/1476-069X-9-12 CrossRefGoogle Scholar
  2. Anderson H, Ponce de Leon A, Bland M et al (1996) Air pollution and daily mortality in London: 1987–92. BMJ 312:665–669CrossRefGoogle Scholar
  3. Ballester F, Corella D, Perez-Hoyos S, Sáez M, Hervás A (1997) Mortality as a function of temperature: a study in Valencia, Spain, 1991–1993. Int J Epidemiol 26:551–561CrossRefGoogle Scholar
  4. Ballester J, Giorgi F, Rodo X (2010) Changes in European temeprature extremes can be predicted from changes in PDF central statistics. Climatic Change 98:277–284. doi: 10.1007/s10584-009-9758-0LETTER Google Scholar
  5. Basu R, Samet J (2002) Relation between elevated ambient temperature and mortality: a review of the epidemiologic evidence. Epidemiol Rev 24:190–202CrossRefGoogle Scholar
  6. Basu R, Feng W, Ostro B (2008) Characterizing temperature and mortality in nine California counties. Epidemiology 19(1):138–145. doi: 10.1097/EDE.0b013e31815c1da7 CrossRefGoogle Scholar
  7. Biostatistics and Medical Informatics and Health System’s Central Administration (2001) The heat index “equation.” National Weather Service Technical Attachment P – Portal de Codificação dos GDH. Available from (Accessed 10 February 2011)
  8. Borrel C, Dell’Olmo M, Rodríguez-Sanz M, Garcia-Olalla P, Cayla J, Benach J, Muntaner C (2006) Socioeconomic position and excess mortality during the heat wave of 2003 in Barcelona. Eur J Epidemiol 21:633–640. doi: 10.1007/s10654-006-9047-4 CrossRefGoogle Scholar
  9. Bouchama A, Knochel J (2002) Heat stroke. N Engl J Med 346(25):1978–1988CrossRefGoogle Scholar
  10. Buechley R, Van Bruggen J, Truppi L (1972) Heat island equals death island? Environ Res 5(1):85–92CrossRefGoogle Scholar
  11. Calado R, Nogueira P, Catarino J, Paixão E, Botelho J, Carreira M, Falcão J (2004) A onda de calor de Agosto de 2003 e os seus efeitos sobre a mortalidade da população portuguesa. Revista Portuguesa de Saúde Pública 22(2):7–20Google Scholar
  12. Conti S, Meli P, Minelli G et al (2005) Epidemiologic study of mortality during the summer 2003 heat wave in Italy. Environ Res 98(3):390–399. doi: 10.1016/j.envres.2004.10.009 CrossRefGoogle Scholar
  13. Dessai S (2002) Heat stress mortality in Lisbon part I—model construction and validation. Int J Biometeorol 47:6–12CrossRefGoogle Scholar
  14. Dessai S (2003) Heat stress mortality in Lisbon part II—an assessment of the potential impacts of climate change. Int J Biometeorol 48:37–44. doi: 10.1007/s00484-003-0180-4 CrossRefGoogle Scholar
  15. Díaz J, Garcia R, Lopez C, Jordan A (2002a) Heat waves in Madrid 1986–1997: effects on the health of the elderly. Int Arch Occup Environ Health 75:163–170. doi: 10.1007/s00420-001-0290-4 CrossRefGoogle Scholar
  16. Díaz J, Garcia R, Velasquez de Castro F, Hernandez E, Lopez C, Otero A (2002b) Effects of extremely hot days on people older than 65 years in Seville (Spain) from 1986 to 1997. Int J Biometeorol 46:145–149. doi: 10.1007/s00484-002-0129-z CrossRefGoogle Scholar
  17. Díaz J, Garcia-Herrera TR, Linares C (2006) The impact of summer 2003 heat wave in Iberia: how should we measure it? Int J Biometeorol 50:159–166. doi: 10.1007/s00484-005-0005-8 CrossRefGoogle Scholar
  18. D’lppoliti D, Michelozzi P, Marino C, Donato F, Menne B, Katsouyanni K, Kirchmayer U, Analitis A, Medina-Ramón M, Paldy A, Atkinson R, Kovats S, Bisanti L, Schneider A, Lefranc A, Iñiguez C, Perucci C (2010) The impact of heat waves on mortality in 9 European cities: results from the EuroHEAT project. Environ Health 9:37. doi: 10.1186/1476-069X-9-37 CrossRefGoogle Scholar
  19. Ellis F, Nelson F (1975) Mortality in the elderly in a heat wave in New York City. Environ Res 978(15):504–512Google Scholar
  20. Ellis F, Nelson F, Pincus L (1975) Mortality during heat waves in New York City July, 1972 and August and September, 1973. Environ Res 10:1–13CrossRefGoogle Scholar
  21. Faraway J (2006) Extending the Linear Model with R. Generalized linear, mixed effects and nonparametric regression models. Chapman and Hall/CRC, LondonGoogle Scholar
  22. Fischer P, Brunekreef B, Lebret E (2004) Air pollution related deaths during the 2003 heat wave in the Netherlands. Atmos Environ 38:1083–1085CrossRefGoogle Scholar
  23. Fouillet A, Rey G, Laurent F, Pavillon G, Bellee S, Guihenneue-Jouyaux CJ, Jougla E, Hémon D (2006) Excess Mortality related to the August 2003 Heat Wave in France. Int Arch Occup Environ Health 80:16–24. doi: 10.1007/s00420-006-0089-4 CrossRefGoogle Scholar
  24. Frota A, Schiffer S (1987) Manual de Conforto Térmico, 5th edn. Studio Nobel, São PauloGoogle Scholar
  25. Garssen J, Harmsen C, De Beer J (2005) The effect of the summer 2003 heat wave on mortality in the Netherlands. Euro Surveill 10(7),
  26. Gosling SN, McGregor GR, Lowe JA (2009) Climate change and heat-related mortality in six cities. Part 2: climate model evaluation and projected impacts from changes in the mean and variability of temperature with climate change. Int J Biometeorol 53:31–51, doi:  10.1007/s00484-008-0189-9 Google Scholar
  27. Grize L, Hussa A, Thommena O, Schindlera C, Braun-Fahrländera C (2005) Heat wave 2003 and mortality in Switzerland. Swiss Med Wkly 135:200–205Google Scholar
  28. Hajat S, Kovats R, Atkinson R, Haines A (2002) Impact of hot temperatures on death in London: a time series approach. J Epidemiol Commun Health 56:367–372. doi: 10.1136/jech.56.5.367 CrossRefGoogle Scholar
  29. Hajat S, Armstrong B, Bacini M, Biggeri A, Bisanti L, Russo A et al (2006) Impact of high temperature on mortality: is there an added heat wave effect? Epidemiology 17:632–638Google Scholar
  30. Hertel S, Tertre A, Jockel K, Hoffmann B (2009) Quantification of the Heat Wave effect on cause-specific Mortality in Essen, Germany. Eur J Epidemiol 24:407–414. doi: 10.1007/s10654-009-9359-2 CrossRefGoogle Scholar
  31. Huang W, Kan H, Kovats S (2010) The impact of the 2003 heat wave on mortality in Shanghai, China. Sci Total Environ 408:2418–2420Google Scholar
  32. Hutter P, Moshammer H, Wallner P, Leitner B, Kundi M (2007) Heatwaves in Vienna: effects on mortality. Wien Klin Wochenschr 119(7–8):223–227. doi: 10.1007/s00508-006-0742-7 CrossRefGoogle Scholar
  33. Huynen M, Martens P, Schram D, Weijenberg M, Kunst A (2001) The impact of heat waves and cold spells on mortality rates in the Dutch population. Environ Health Perspect 109(5):463–470CrossRefGoogle Scholar
  34. Jendritzky G (1993) Human biometeorology part I. Experientia 499:733–740CrossRefGoogle Scholar
  35. Johnson H, Kovats S, McGregor G et al (2005) The impact of the 2003 Heat Wave on daily mortality in England and Wales and the use of rapid weekly mortality estimates. Euro Surveill 10(7),
  36. Keatinge W, Coleshaw S, Easton J, Cotter F, Mattock M, Chelliah R (1986) Increased platelet and red cell counts, blood viscosity, and plasma cholesterol levels during heat stress, and mortality from coronary and cerebral thrombosis. Am J Med 81:795–800CrossRefGoogle Scholar
  37. Kenney W (1997) Thermoregulation at rest and during exercise in healthy older adults. Exercise Sport Sci R 25:41–76Google Scholar
  38. Kilbourne E (1999) The spectrum of illness during Heat Waves. Am J Prev Med 16(4):359–360CrossRefGoogle Scholar
  39. Klinenberg E (2002) Heat Wave: a social autopsy of disaster in Chicago. Chicago: University of Chicago Press, 305 pp. ISBN 0-226-44321-3Google Scholar
  40. Koppe C, Jendritzky G, Kovats R, Menne B (2003) Heatwaves: impacts and responses. World Health Organization, CopenhagenGoogle Scholar
  41. Kovats R, Ebi K (2006) Heatwaves and public health in Europe. Eur J Public Health 16(6):592–599. doi: 10.1093/eurpub/ckl049 CrossRefGoogle Scholar
  42. Kyselý J (2004) Mortality and displaced mortality during Heat Waves in the Czech Republic. Int J Biometeorol 49:91–97. doi: 10.1007/s00484-004-0218-2 CrossRefGoogle Scholar
  43. Liang WM, Liu WP, Chou SY, Kuo HW (2008) Ambient temperature and emergency room admissions for acute coronary syndrome in Taiwan. Int J Biometeorol 52:223–229Google Scholar
  44. Linares D, Díaz J (2007) Impact of high Temperatures on hospital admissions: comparative analysis with previous studies about mortality (Madrid). Eur J Public Health 18(3):317–322. doi: 10.1093/eurpub/ckm108 CrossRefGoogle Scholar
  45. Mastrangelo G, Fedeli U, Visentin C, Milan G, Fadda E, Spolaore P (2007) Pattern and determinants of hospitalization during Heat Waves: an ecologic study. BMC Public Health 7:200. doi: 10.1186/1471-2458-7-200 CrossRefGoogle Scholar
  46. McGeehin M, Mirabelli M (2001) The potential impacts of climate variability and change on temperature related morbidity and mortality in the United States. Environ Health Perspect 109(Suppl 2):185–189CrossRefGoogle Scholar
  47. Meehl G, Tebaldi C (2004) More intense, more frequent, and longer lasting Heat Waves in the 21st century. Science 305:994–997. doi: 10.1126/science.1098704 CrossRefGoogle Scholar
  48. Michelozzi P, Sario M, Acetta G, Donato F, Kirchmayer U, Ovidio M, Perucci C (2006) Temperature and summer mortality: geographical and temporal variations in four Italian cities. J Epidemiol Community Health 60:417–423. doi: 10.1136/jech.2005.040857 CrossRefGoogle Scholar
  49. Michelozzi P et al (2009) High temperature and hospitalizations for cardiovascular and respiratory causes in 12 European cities. Am J Respir Crit Care Med 179:383–389CrossRefGoogle Scholar
  50. National Institute of Statistics (2001) General population and northern region’s housing census. Available from (Accessed 1 April 2011)
  51. National Weather Service Weather Forecast Office (Accessed April 2011) Summer Weather Safety and Survival. Heat Index. Available from (Accessed 10 February 2011)
  52. Naughton M, Henderson A, Mirabelli M, Kaiser R, Wilhelm J, Kieszak S, Rubin C, McGeehin M (2002) Heat-related mortality during a 1999 Heat Wave in Chicago. Am J Prev Med 22(4):221–227CrossRefGoogle Scholar
  53. Nogueira P, Falcao J, Contreiras M et al (2005) Mortality in Portugal associated with the Heat Wave of August 2003: early estimation of effect, using a rapid method. Euro Surveill 10(7):150–153 (Accessed 15 October 2011)
  54. Pirard P, Vandentorren S, Pascal M, Laaidi K, Le Tertre A, Cassadou S, Ledrans M (2005) Summary of the Mortality impact assessment of the 2003 Heat Wave in France. Euro Surveill 10(7) Available online: (Accessed 13 February 2011)
  55. Planton S, Déqué M, Chauvin F, Terray L (2008) Expected impacts of climate change on extreme climate events. C R Geosci 340:564–574. doi: 10.1016/j.crte.2008.07.009 CrossRefGoogle Scholar
  56. Rey G, Jougla E, Fouillet A, Pavillon G, Bessemoulin P, Fraussinet P, Clavel J, Hémon D (2007) The impact of major hear waves on all-cause and cause-specific mortality in France from 1971 to 2003. Int Arch Occup Environ Health 80:615–626. doi: 10.1007/s00420-007-0173-4 CrossRefGoogle Scholar
  57. Rooke G, Savage M, Brengelmann G (1994) Maximal skin blood flow is decreased in elderly men. J Appl Physiol 77:11–14Google Scholar
  58. Rooney C, McMichael A, Kovats R, Coleman M (1998) Excess Mortality in England and Wales, and in Greater London, during the 1995 heatwave. J Epidemiol Community Health 482(52):482–486CrossRefGoogle Scholar
  59. Rothfusz L (1990) The heat index “equation.” National Weather Service Technical Attachment (SR 90–23)Google Scholar
  60. Saez M, Sunyer J, Castellsagué J, Murillo C, Antó J (1995) Relationship between weather temperature and mortality: a time series analysis approach in Barcelona. Int J Epidemiol 24:576–582CrossRefGoogle Scholar
  61. Schiffano P, Cappai G, Sario M, Michelozzi P, Marino C, Bargagli A, Peruci C (2009) Susceptibility to Heat Wave-related mortality: a follow-up study of a cohort of elderly in Rome. Environ Health 8:50. doi: 10.1186/1476-069X-8-50 CrossRefGoogle Scholar
  62. Schulman S, Lakatta E, Fleg J, Lakatta L, Becker L, Gerstenblith G (1992) Age related decline in left ventricular filling at rest and exercise. Am J Physiol 263:1932–1938Google Scholar
  63. Semenza J, Carol M, Rubin H, Kenneth M, Falter H, Selanikio J, Flanders D, Howe H, Wilhelm J (1996) Heat-related deaths during the July 1995 Heat Wave in Chicago. New Engl J Med 335(2):84–90CrossRefGoogle Scholar
  64. Semenza J, McCullough J, Flanders W, McGeehin M, Lumpkin J (1999) Excess hospital admissions during the July 1995 Heat Wave in Chicago. Am J Prev Med 16(4):269–277CrossRefGoogle Scholar
  65. Simon F, Lopez-Abente G, Ballester E, Martinez F (2005) Mortality in Spain during the Heat Waves of summer 2003. Euro Surveill 10(7). Available online:
  66. Steadman R (1979a) The assessment of sultriness. Part I: A temperature-humidity index based on human physiology and clothing science. J Appl Meteorol 18(7):861–873CrossRefGoogle Scholar
  67. Steadman R (1979b) The assessment of sultriness. Part II: Effect of wind, extra radiation, and barometric pressure on Apparent Temperature. J Appl Meteorol 18(7):874–884CrossRefGoogle Scholar
  68. Steadman R (1984) A Universal Scale of Apparent Temperature. J Clim Appl Meteorol 23(12):1674–1687CrossRefGoogle Scholar
  69. Stedman J (2004) The predicted number of Air Pollution related deaths in the UK during the August 2003 heatwave. Atmos Environ 38:1087–1090CrossRefGoogle Scholar
  70. Tan J, Zheng Y, Song G, Kalkstein L, Kalkstein J, Tang X (2007) Heat Wave impacts on Mortality in Shanghai, 1998 and 2003. Int J Biometeorol 51:193–200. doi: 10.1007/s00484-006-0058-3 CrossRefGoogle Scholar
  71. Tan J, Zheng Y, Tang X, Guo C, Li L, Song G, Zhen X, Yuan D , Kalkstei A, Li F, Chen H (2010)The urban heat island and its impact on Heat Waves and human health in Shanghai. Int J Biometeorol 54:75–84doi:  10.1007/s00484-009-0256-x Google Scholar
  72. Weisskopf M, Anderson H, Foldy S, Hanrahan L, Blair K, Török T, Rumm P (2002) Heat Wave morbidity and mortality, Milwaukee, Wis, 1999 vs 1995: an improved response? Am J Publ Health Res Pract 92(5):830–833CrossRefGoogle Scholar
  73. Whitman S, Good G, Donoghue E, Benbow N, Shou W, Mou S (1997) Mortality in Chicago attributed to the July 1995 Heat Wave. Am J Public Health 87(9):1515–1518CrossRefGoogle Scholar

Copyright information

© ISB 2012

Authors and Affiliations

  • Ana Monteiro
    • 1
  • Vânia Carvalho
    • 2
  • Teresa Oliveira
    • 1
  • Carlos Sousa
    • 1
  1. 1.Department of Geography, Public Health InstitutePorto UniversityPortoPortugal
  2. 2.FMUP, Public Health InstitutePorto UniversityPortoPortugal

Personalised recommendations