title: Ambient temperature and morbidity: a review of epidemiological evidence.
abstract: OBJECTIVE
  In this paper, we review the epidemiological evidence on the relationship between ambient temperature and morbidity. We assessed the methodological issues in previous studies and proposed future research directions.
  
  
  METHODS
  We searched the PubMed database for epidemiological studies on ambient temperature and morbidity of noncommunicable diseases published in refereed English journals before 30 June 2010. Forty relevant studies were identified. Of these, 24 examined the relationship between ambient temperature and morbidity, 15 investigated the short-term effects of heat wave on morbidity, and 1 assessed both temperature and heat wave effects.
  
  
  RESULTS
  Descriptive and time-series studies were the two main research designs used to investigate the temperature-morbidity relationship. Measurements of temperature exposure and health outcomes used in these studies differed widely. The majority of studies reported a significant relationship between ambient temperature and total or cause-specific morbidities. However, there were some inconsistencies in the direction and magnitude of nonlinear lag effects. The lag effect of hot temperature on morbidity was shorter (several days) compared with that of cold temperature (up to a few weeks). The temperature-morbidity relationship may be confounded or modified by sociodemographic factors and air pollution.
  
  
  CONCLUSIONS
  There is a significant short-term effect of ambient temperature on total and cause-specific morbidities. However, further research is needed to determine an appropriate temperature measure, consider a diverse range of morbidities, and to use consistent methodology to make different studies more comparable.
authors.affiliation: School of Public Health and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Ye
authors.forename: Rodney
authors.initials: R
authors.lastname: Wolff
authors.forename: Weiwei
authors.initials: W
authors.lastname: Yu
authors.forename: Pavla
authors.initials: P
authors.lastname: Vaneckova
authors.forename: Xiaochuan
authors.initials: X
authors.lastname: Pan
authors.forename: Shilu
authors.initials: S
authors.lastname: Tong
mesh_terms: D057231:Climate Change; D016021:Epidemiologic Studies; D018882:Heat Stress Disorders / Q000453:epidemiology; D006760:Hospitalization; D006358:Hot Temperature; D006801:Humans; D009017:Morbidity