title: The effects of summer temperature and heat waves on heat-related illness in a coastal city of China, 2011-2013.
abstract: BACKGROUND
  Devastating health effects from recent heat waves in China have highlighted the importance of understanding health consequences from extreme heat stress. Despite the increasing mortality from extreme heat, very limited studies have quantified the effects of summer extreme temperature on heat-related illnesses in China.
  
  
  METHODS
  The associations between extreme heat and daily heat-related illnesses that occurred in the summers of 2011-2013 in Ningbo, China, have been examined, using a distributed lag non-linear model (DLNM) based on 3862 cases. The excess morbidities of heat-related illness during each heat wave have been calculated separately and the cumulative heat wave effects on age-, sex-, and cause-specific illnesses in each year along lags have been estimated as well.
  
  
  RESULTS
  After controlling the effect of relative humidity, it is found that maximum temperature, rather than heat index, was a better predictor of heat-related illnesses in summers. A positive association between maximum temperatures and occurrence of heat-related diseases was apparent, especially at short lag effects. Six heat waves during the period of 2011-2013 were identified and all associated with excess heat-related illnesses. Relative to the average values for the corresponding periods in 2011 and 2012, a total estimated 679 extra heat-related illnesses occurred during three heat waves in 2013. The significant prolonged heat wave effects on total heat-related illnesses during heat waves in three study years have also been identified. The strongest cumulative effect of heat waves was on severe heat diseases in 2013, with a 10-fold increased risk. More males than females, individuals with more severe forms of illness, were more affected by the heat. However, all age groups were vulnerable.
  
  
  CONCLUSIONS
  Recent heat waves had a substantial and delayed effect on heat illnesses in Ningbo. Relevant active well-organized public health initiatives should be implemented to reduce the adverse effects of heat extremes on the illnesses.
authors.affiliation: State Key Laboratory for Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China. Electronic address: baili_ChinaCDC@163.com.
authors.forename: Li
authors.initials: L
authors.lastname: Bai
authors.affiliation: Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China. Electronic address: gqding@cdc.zj.cn.
authors.forename: Gangqiang
authors.initials: G
authors.lastname: Ding
authors.affiliation: State Key Laboratory for Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China. Electronic address: gushaohua1989@sina.com.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Gu
authors.affiliation: School of Population Health, University of Adelaide, South Australia 5005, Australia. Electronic address: peng.bi@adelaide.edu.au.
authors.forename: Peng
authors.initials: P
authors.lastname: Bi
authors.affiliation: National Climate Center, Beijing 100081, China. Electronic address: subd@cma.gov.cn.
authors.forename: Buda
authors.initials: B
authors.lastname: Su
authors.affiliation: National Climate Center, Beijing 100081, China. Electronic address: qdh@cma.gov.cn.
authors.forename: Dahe
authors.initials: D
authors.lastname: Qin
authors.affiliation: Ningbo Center for Disease Control and Prevention, Ningbo 315010, China. Electronic address: xugz@nbcdc.org.cn.
authors.forename: Guozhang
authors.initials: G
authors.lastname: Xu
authors.affiliation: State Key Laboratory for Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 155 Changbai Road, Changping District, Beijing 102206, China; Shandong University Climate Change and Health Center, Jinan 250100, China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou 310003, China. Electronic address: liuqiyong@icdc.cn.
authors.forename: Qiyong
authors.initials: Q
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D002947:Cities / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D018882:Heat Stress Disorders / Q000453:epidemiology*; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D055815:Young Adult
keywords: China; Heat stroke; Heat waves; Heat-related illness; Temperature