Global climate change: impact of heat waves under different definitions on daily mortality in Wuhan, China
© The Author(s) 2017
Received: 15 November 2016
Accepted: 20 February 2017
Published: 5 April 2017
There was no consistent definition for heat wave worldwide, while a limited number of studies have compared the mortality effect of heat wave as defined differently. This paper aimed to provide epidemiological evidence for policy makers to determine the most appropriate definition for local heat wave warning systems.
We developed 45 heat wave definitions (HWs) combining temperature indicators and temperature thresholds with durations. We then assessed the impact of heat waves under various definitions on non-accidental mortality in hot season (May–September) in Wuhan, China during 2003–2010.
Heat waves defined by HW14 (daily mean temperature ≥ 99.0th percentile and duration ≥ 3 days) had the best predictive ability in assessing the mortality effects of heat wave with the relative risk of 1.63 (95% CI: 1.43, 1.89) for total mortality. The group-specific mortality risk using official heat wave definition of Chinese Meteorological Administration was much smaller than that using HW14. We also found that women, and the elderly (age ≥ 65) were more susceptible to heat wave effects which were stronger and longer lasting.
These findings suggest that region specific heat wave definitions are crucial and necessary for developing efficient local heat warning systems and for providing evidence for policy makers to protect the vulnerable population.
KeywordsClimate change Temperature Heat wave Definition Mortality China
Global climate change has become one of the biggest health threats in the 21st century . As increased frequency, intensity, and duration of heat wave events occurred associated with global warming [2–4], impact of heat wave on health has drawn more and more attention worldwide. For instance, California heat wave occurring in 2006 was reported to be associated with approximately 16,166 excess emergency department visits and 1182 excess hospitalizations . And in the summer of 2010, Moscow and Western Russia suffered an unprecedented heat wave both in strength and duration, resulting in 55,000 excess heat-related deaths . From a pathophysiological point of view, heat waves were associated with dehydration, increased blood viscosity and impairment of the endothelial function, which would in return increase the risk for thrombo-embolic diseases and cardiovascular events .
Until now, there has been no single, consistent definition of heat waves as people may acclimatize themselves to their local climatic zones [8, 9]. In general, heat waves are defined by (1) temperature indicator (e.g., daily average, maximum, or minimum temperature), (2) temperature threshold (e.g., a relative threshold or an absolute threshold), and (3) heat wave duration . Many previous studies applied several heat wave definitions as sensitivity analyses when assessing the health impact of heat wave [11, 12]. However, heat-related mortality risk estimates varied greatly by different heat wave definitions according to several recent studies [10, 13, 14], which demonstrated the importance of heat wave definitions in predicting health effects of heat waves. Moreover, by using the variance-decomposition method, heat wave definitions were found to attribute to 22.2% of the uncertainty for mortality risks during future heat waves in a recent study conducted in the Eastern United States . Hence, it is of great significance to determine the most appropriate definition for heat wave warning systems based on local epidemiological studies.
People in developing countries are more susceptible to heat-related mortality than developed countries due to limited adaptive capacity and vulnerability . However, most of heat-related epidemiological studies were conducted in developed countries (e.g., USA and European countries) [2, 4]. As the largest developing country, China has experienced a rapid aging of the population in recent years , which may also lead to an increased health burden from heat . Nevertheless, only a limited number of studies have explored the adverse health impact of heat wave in China, especially in the inland provinces including some major cities .
In this study we assessed the impact of heat waves under various definitions on daily mortality in Wuhan, China during 2003–2010, and aimed to provide epidemiological evidence for policy makers to determine the most appropriate definition for local heat wave warning systems.
Study area and population
Wuhan, the capital of Hubei Province and the largest city in central China, is located in the middle of the Yangtze River Delta, at 29°58´–31°22´ north latitude and 113°41´–115°05´ east longitude. Wuhan has typical subtropical, humid, monsoon climate with a distinct pattern of four seasons. Jiang’an District is one of the seven main central urban districts in Wuhan and was the political, economic, cultural, financial, and information center of Wuhan City. The resident population of Jiang’an District was about 0.68 million in 2010 and urban area was 64.24 km2. Known as an oven city in China, Wuhan usually experienced very hot summers, with the highest maximum temperature of 39.6 °C during 2003–2010.
Daily mortality data from January 1, 2003 to December 31, 2010 were obtained from Centre for Disease Control and Prevention of Jiang’an District in Wuhan, China. The causes of death were encoded according to the 10th Revision of the International Classification of Disease (ICD-10) and daily non-accidental death (A00-R99) was collected in the present study. Daily meteorological data during 2003–2010, including daily maximum, mean, minimum temperature and relative humidity were obtained from the China Meteorological Data Sharing Service System (http://data.cma.cn/). Daily air pollution data of particulate matter < 10 μm in aerodynamic diameter (PM10), sulfur dioxide (SO2), and nitrogen dioxide (NO2) were collected from the Wuhan Environmental Monitoring Center. As in previous studies [10, 12], we restricted the study period to the hot season (May–September) when heat waves generally occurred in Wuhan.
Heat wave definition
In order to determine which heat wave definition is the best to capture the effects on non-accidental mortality in Wuhan, we developed 45 heat wave definitions combining temperature indicators (mean temperature, maximum temperature, and minimum temperature), temperature thresholds [8, 10, 19] (90.0th, 92.5th, 95th, 97.5th, and 99.0th percentile of daily mean/maximum/minimum temperature during 2003–2010) with duration of ≥2, ≥3, and ≥4 days.
Y t and μ t are the observed and expected daily number of non-accidental death on day t, respectively. α is the intercept, and ns refers to natural cubic spline. doy and Rh mean day of the year and relative humidity, respectively. HWs represents the binary variable for heat waves under different definitions.
According to a previous study , we assessed the best model fit among the 45 various heat wave definitions by minimizing the sum of the Akaike Information Criterion for quasi-Poisson (Q-AIC) values from all group-specific mortality (total, male, female, age < 65, and age ≥ 65). In addition, we compared the mortality risks of heat wave defined by Chinese Meteorological Administration [21, 22] (HWCMA, daily maximum temperature ≥35 °C and duration ≥ 3 days) with the most appropriate definition determined by the above criterion.
To demonstrate the association between mortality and heat wave more comprehensively, we also conducted the lag effect analyses (lag0 to lag10) of heat waves, which separately assessed the mortality impact several days (0 to 10) posterior to heat waves. Mortality effects of heat waves at lag1 day, for instance, were assessed by linking heat wave exposure (i.e. heat-wave day or non-heat-wave day) 1 day prior to deaths with the non-accidental deaths on the current day.
Sensitivity analyses were performed by changing the df (5 to 8) for day of the year to control for seasonality and df (4 to 6) for relative humidity. Besides, we examined the possible confounding effects of air pollutants (i.e., PM10, SO2, and NO2) since short-term exposures to these pollutants were also found associated with daily mortality in numerous epidemiological studies. Additionally, we verified the model fits of different heat wave definitions by using another evaluation standard (Bayesian information criterion for quasi-Poisson, Q-BIC).
All analyses were conducted with R software (version 3.1.3; http://www.r-project.org/). The statistical tests were two-sided, and effects of P < 0.05 were considered statistically significant.
Descriptive statistics of daily death, meteorological factors and concentrations of air pollutants
Descriptive statistics of daily death, meteorological factors and concentrations of air pollutants in hot season (May–September) in Wuhan, China during 2003–2010
Mean ± SD
9.7 ± 3.3
5.4 ± 2.4
4.3 ± 2.3
Age < 65
2.7 ± 1.6
Age ≥ 65
7.0 ± 2.9
Minimum temperature (°C)
23.6 ± 3.8
Mean temperature (°C)
26.7 ± 3.9
Maximum temperature (°C)
30.9 ± 4.2
Relative humidity (%)
71.4 ± 10.7
Air Pollutants (μg/m3)
90.5 ± 44.0
35.4 ± 19.7
46.4 ± 18.9
Heat wave definitions and model fits using Q-AIC values for different heat wave definitions
The 46 heat wave definitions (HW01-HW45, and HWCMA) and the sum of Q-AIC values from all group-specific mortality for different heat wave definitions in hot season (May–September) in Wuhan, China during 2003–2010
Definitions and Q-AIC values
Duration ≥ 2 days
Duration ≥ 3 days
Duration ≥ 4 days
P90.0 (29.8 °C)
P92.5 (30.7 °C)
P95.0 (31.7 °C)
P97.5 (32.6 °C)
P99.0 (33.3 °C)
P90.0 (34.2 °C)
P92.5 (35.2 °C)
P95.0 (35.9 °C)
P97.5 (36.7 °C)
P99.0 (37.4 °C)
P90.0 (26.5 °C)
P92.5 (27.3 °C)
P95.0 (28.3 °C)
P97.5 (29.3 °C)
P99.0 (30.2 °C)
Additional file 1: Table S1 shows that the number of heat-wave days and daily deaths during 2003–2010 in Wuhan under 45 different heat wave definitions. Similar number of heat-wave days and daily deaths were identified using daily maximum/minimum temperature metric and daily mean temperature metric in heat wave definitions. Less heat-wave days and more daily deaths on heat-wave days occurred when heat waves were defined by higher percentile of temperature thresholds and longer durations, while daily deaths on non-heat-wave days changed little along with heat wave definitions.
Mortality effects of heat wave under 45 different definitions
Group-specific mortality effects of heat wave using HW14, HW29, HW43, and HWCMA
Relative risk of group-specific mortality on heat-wave days compared with non-heat-wave days (using heat wave definition HW14, HW29, HW43, and HWCMA) with and without adjusting for air pollutants in Wuhan, China during 2003–2010
Heat wave definition
Age < 65
Age ≥ 65
Age < 65
Age ≥ 65
Age < 65
Age ≥ 65
Age < 65
Age ≥ 65
Lag patterns and group-specific mortality effects of heat wave using HW14 and HWCMA
Our sensitivity analyses indicated that estimated mortality risks were robust when changing the df (5 to 8) for day of the year (Additional file 1: Figure S1) and df (4 to 6) for relative humidity (Additional file 1: Figure S2). Associations between heat waves and daily mortality almost kept unchanged with and without adjusting for air pollutants (Table 3). Similar model fits were consistently observed by using Q-BIC as the evaluation standard, which also determined HW14 as the best predictive ability in assessing the mortality effects of heat wave (Additional file 1: Table S2).
In this study, we evaluated which of the 46 heat wave definitions can best capture the heat wave impact on non-accidental mortality in Wuhan during 2003 to 2010. Compared with non-heat-wave days, heat waves defined by HW14 (daily mean temperature ≥ 99th percentile and duration ≥ 3 days) performed best in predicting the effects of heat wave on group-specific mortality. The estimated mortality effects of heat waves almost kept unchanged with and without adjusting for air pollutants (PM10, SO2, and NO2). We also found that females and the elderly were more susceptible to heat wave effects which were stronger and longer lasting. These findings may have important implications for public health policies to protect people from extremely hot temperatures in Wuhan, China.
Our results found that heat waves were associated with increased daily mortality in Wuhan, which were consistent with several previous studies [23–26]. However, the heat-related mortality in different regions varied greatly . National-level analyses conducted in 66 Chinese communities  and 43 U.S. communities  showed that the morality risks of heat wave were spatially heterogeneous with greater effects in the northern regions and smaller in the southern regions. The differences revealed that population susceptibility to heat wave may be discrepant due to acclimatization to local climate characteristics through long-term physiological and behavioral adaptation [20, 29]. In addition, socioeconomic factors such as average income, health care system, population density and numbers of household-owned air conditionings were found to modify the health impact of heat wave [30, 31].
A number of previous studies revealed that gender and age might modify the associations between environmental risk factors (such as air pollution, extremely temperature events) and daily mortality [25, 32–34]. In the present study, we found that the elderly were more vulnerable to heat wave-related mortality, which might be due to the reduced thermoregulatory capacity, the status of on medication that may interfere with normal sweating process, low risk perception and adaptation ability to heat wave [12, 20]. The impact of heat wave may become a great health and social burden in the next few decades in China due to the rapid population aging, which demonstrated the importance and urgency for decision makers and the public to design adaptation plan to heat wave for elderly people . Consistent with most studies focusing on temperature-related mortality [1, 2, 12], our results showed a stronger association in females than that in males between heat wave and mortality. However, this finding was less consistent with several other studies [23, 35].
In China, heat wave was nationwide defined as daily maximum temperature ≥35 °C with duration ≥3 days by Chinese Meteorological Administration (CMA). However, some studies indicated that it might be inappropriate for a large country like China to use an absolute temperature as the threshold for defining heat waves due to the variable vulnerability to heat waves in different regions [10, 20]. The health impact of heat wave under different definitions had been examined in two previous studies conducted in Beijing  and Nanjing, China . Tian et al. compared 18 heat wave definitions by combining heat wave thresholds (87.5th, 90.0th, 92.5th, 95th, 97.5th, and 99th percentile of daily mean temperature) with different duration days (≥2 to ≥ 4 days) to assess the short-term impact of heat waves on CHD mortality, and found that heat wave definition using 97.5th percentile of daily mean temperature and duration ≥2 days produced the best model fit  . Chen et al. reported that heat waves defined as ≥4 consecutive days with daily mean temperature >98th percentile were the most appropriate to estimate the influence of the added effect of heat waves on cause-specific mortality in Nanjing among 15 heat wave definitions . In our study, heat wave defined by HW14 (daily mean temperature >99th percentile and duration ≥3 days) showed the best predictive ability in evaluating heat wave-mortality relationship, and using the CMA definition underestimated the mortality risks of heat waves in Wuhan. Therefore, region specific definitions based on relative temperature thresholds are needed to design effective local heat warning systems . In addition, our results showed that, with the same relative thresholds and durations, heat waves using daily maximum/minimum temperature metrics and daily mean temperature metric had similar estimates of mortality risks, which was consistent with previous studies focusing on temperature-mortality relationship [36, 37]. However, daily mean temperature can capture heat wave effects more completely in the present study, and mean temperature was most commonly used to assess the association between temperature and mortality since mean temperature can represent the exposure throughout the whole day and night and provide more easily interpreted results within a policy context [2, 38].
Previously, a positive association between ambient pollutants and daily mortality has been clearly demonstrated in numerous epidemiological studies. In the present study, we observed that heat wave effects on mortality remained similar with and without adjusting for air pollutants (PM10, SO2, and NO2), even though the concentrations of air pollutants were well above the international health-based standards. Consistent results were also obtained in two recent Chinese studies, one of which was conducted in Nanjing using 18 different definitions of heat wave . The other was conducted in four communities of Guangdong Province using daily API (Air Pollution Index) as the substitutive indicator of air pollution . These studies provided implications for the future researchers that air pollutants would not significantly change the estimated mortality risk of temperature, thus we can also approximately assess the temperature-related health effects without availability of air pollution data.
Our study has several limitations. Firstly, the daily mortality data were obtained from only one district of Wuhan City, which may not completely capture the effects of heat wave in the whole city. Secondly, we did not consider the possible interactions between air pollution and high temperature in the analyses, which might result in overestimated heat wave effects if air pollution and high temperature had synergistic effects on mortality . Thirdly, a number of other thermal indicators, such as ambient apparent temperature, could also be used to define the heat wave. However, we only included daily mean, maximum, and minimum temperature in the present study considering that these are most commonly used heat-related indicators, and can be easily understood by the public. In addition, the influence of ozone on mortality was not included in the analyses due to the unavailability of ozone data. However, the present and previous studies showed that heat-related mortality effects were robust after adjusting for air pollution [10, 39].
Our study demonstrated a significant increase in mortality during heat wave in Wuhan, China, while the mortality effects of heat waves varied greatly by different heat wave definitions. It was suggested to use daily mean temperature ≥ 33.3 °C (99th percentile) with duration ≥3 days as heat wave definition in Wuhan, as it could best capture the mortality effects of heat wave. Our results also showed that the elderly and females were more vulnerable to the mortality impact of heat waves. These findings suggest that region specific heat wave definitions are crucial and necessary for developing efficient local heat warning systems and providing evidence for policy makers to protect the vulnerable individuals.
Chinese Meteorological Administration
Degree of freedom
Day of the week
Generalized linear model
Heat wave definitions
The 10th Revision of the International Classification of Disease
- NO2 :
- PM10 :
Particulate matter < 10 μm in aerodynamic diameter
Akaike Information Criterion for quasi-Poisson
- SO2 :
The authors would like to acknowledge Jiang’an District Center for Disease Control and Prevention, Wuhan, China, for providing mortality data.
No funding was received.
Availability of data and materials
The data supporting the findings presented in this paper can be obtained on request from the corresponding author (Lu Ma, E-Mail: email@example.com; Tel.: +86-27-6875- 8875).
LM and YZ conceived and designed the experiments; RF, RW and PZ collected the data; YZ analyzed the data; KW and XT contributed reagents/materials/analysis tools; YQ and LM wrote the paper. All authors read and approved the final manuscript.
The authors declare that they have no competing interests.
Consent for publication
Ethics approval and consent to participate
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
- Zhou X, Zhao A, Meng X, Chen R, Kuang X, Duan X, Kan H. Acute effects of diurnal temperature range on mortality in 8 Chinese cities. Sci Total Environ. 2014;493:92–7.View ArticlePubMedGoogle Scholar
- Wang C, Chen R, Kuang X, Duan X, Kan H. Temperature and daily mortality in Suzhou, China: a time series analysis. Sci Total Environ. 2014;466–467:985–90.View ArticlePubMedGoogle Scholar
- Gronlund CJ, Zanobetti A, Schwartz JD, Wellenius GA, O’Neill MS. Heat, heat waves, and hospital admissions among the elderly in the United States, 1992–2006. Environ Health Perspect. 2014;122:1187–92.PubMedPubMed CentralGoogle Scholar
- Gao J, Sun Y, Liu Q, Zhou M, Lu Y, Li L. Impact of extreme high temperature on mortality and regional level definition of heat wave: a multi-city study in China. Sci Total Environ. 2015;505:535–44.View ArticlePubMedGoogle Scholar
- Knowlton K, Rotkin-Ellman M, King G, Margolis HG, Smith D, Solomon G, Trent R, English P. The 2006 California heat wave: impacts on hospitalizations and emergency department visits. Environ Health Perspect. 2009;117:61–7.View ArticlePubMedGoogle Scholar
- Shaposhnikov D, Revich B, Bellander T, Bedada GB, Bottai M, Kharkova T, Kvasha E, Lind T, Pershagen G. Long-term impact of moscow heat wave and wildfires on mortality. Epidemiology. 2015;26:e21–2.View ArticlePubMedGoogle Scholar
- Zacharias S, Koppe C, Mücke H-G. Climate Change Effects on Heat Waves and Future Heat Wave-Associated IHD Mortality in Germany. Climate. 2014;3:100–17.View ArticleGoogle Scholar
- Tian Z, Li S, Zhang J, Guo Y. The characteristic of heat wave effects on coronary heart disease mortality in Beijing, China: a time series study. Plos One. 2013;8:e77321.View ArticlePubMedPubMed CentralGoogle Scholar
- Sun X, Sun Q, Zhou X, Li X, Yang M, Yu A, Geng F. Heat wave impact on mortality in Pudong New Area, China in 2013. Sci Total Environ. 2014;493:789–94.View ArticlePubMedGoogle Scholar
- Chen K, Bi J, Chen J, Chen X, Huang L, Zhou L. Influence of heat wave definitions to the added effect of heat waves on daily mortality in Nanjing, China. Sci Total Environ. 2015;506–507:18–25.View ArticlePubMedGoogle Scholar
- Gasparrini A, Armstrong B. The impact of heat waves on mortality. Epidemiology. 2011;22:68–73.View ArticlePubMedPubMed CentralGoogle Scholar
- Zeng W, Lao X, Rutherford S, Xu Y, Xu X, Lin H, Liu T, Luo Y, Xiao J, Hu M, et al. The effect of heat waves on mortality and effect modifiers in four communities of Guangdong Province, China. Sci Total Environ. 2014;482–483:214–21.View ArticlePubMedGoogle Scholar
- Kent ST, McClure LA, Zaitchik BF, Smith TT, Gohlke JM. Heat waves and health outcomes in Alabama (USA): the importance of heat wave definition. Environ Health Perspect. 2014;122:151–8.View ArticlePubMedGoogle Scholar
- Zhang K, Rood RB, Michailidis G, Oswald EM, Schwartz JD, Zanobetti A, Ebi KL, O’Neill MS. Comparing exposure metrics for classifying ‘dangerous heat’ in heat wave and health warning systems. Environ Int. 2012;46:23–9.View ArticlePubMedPubMed CentralGoogle Scholar
- Wu J, Zhou Y, Gao Y, Fu JS, Johnson BA, Huang C, Kim YM, Liu Y. Estimation and uncertainty analysis of impacts of future heat waves on mortality in the eastern United States. Environ Health Perspect. 2014;122:10–6.View ArticlePubMedGoogle Scholar
- Guo Y, Li S, Zhang Y, Armstrong B, Jaakkola JJ, Tong S, Pan X. Extremely cold and hot temperatures increase the risk of ischaemic heart disease mortality: epidemiological evidence from China. Heart. 2013;99:195–203.View ArticlePubMedGoogle Scholar
- Zhang NJ, Guo M, Zheng X. China: awakening giant developing solutions to population aging. Gerontologist. 2012;52:589–96.View ArticlePubMedGoogle Scholar
- Zhang Y, Li C, Feng R, Zhu Y, Wu K, Tan X, Ma L. The Short-Term Effect of Ambient Temperature on Mortality in Wuhan, China: A Time-Series Study Using a Distributed Lag Non-Linear Model. Int J Environ Res Public Health. 2016;13:722.View ArticlePubMed CentralGoogle Scholar
- Xu Z, Fitzgerald G, Guo Y, Jalaludin B, Tong S. Impact of heatwave on mortality under different heatwave definitions: a systematic review and meta-analysis. Environ Int. 2016;89–90:193–203.View ArticlePubMedGoogle Scholar
- Ma W, Zeng W, Zhou M, Wang L, Rutherford S, Lin H, Liu T, Zhang Y, Xiao J, Zhang Y, et al. The short-term effect of heat waves on mortality and its modifiers in China: an analysis from 66 communities. Environ Int. 2015;75:103–9.View ArticlePubMedGoogle Scholar
- Huang W, Kan H, Kovats S. The impact of the 2003 heat wave on mortality in Shanghai, China. Sci Total Environ. 2010;408:2418–20.View ArticlePubMedGoogle Scholar
- Wu K, Zhang Y, Zhu C, Ma L, Tan X. Association between heat wave and stroke mortality in Jiang’an District of Wuhan, China during 2003 to 2010: a time-series analysis. Chin J Cardiol. 2015;43:1092–6.Google Scholar
- Tan J, Zheng Y, Song G, Kalkstein LS, Kalkstein AJ, Tang X. Heat wave impacts on mortality in Shanghai, 1998 and 2003. Int J Biometeorol. 2007;51:193–200.View ArticlePubMedGoogle Scholar
- Morignat E, Perrin JB, Gay E, Vinard JL, Calavas D, Henaux V. Assessment of the impact of the 2003 and 2006 heat waves on cattle mortality in France. Plos One. 2014;9:e93176.View ArticlePubMedPubMed CentralGoogle Scholar
- Azhar GS, Mavalankar D, Nori-Sarma A, Rajiva A, Dutta P, Jaiswal A, Sheffield P, Knowlton K, Hess JJ, Ahmedabad HeatClimate Study G. Heat-related mortality in India: excess all-cause mortality associated with the 2010 Ahmedabad heat wave. Plos One. 2014;9:e91831.View ArticlePubMedPubMed CentralGoogle Scholar
- D’Ippoliti D, Michelozzi P, Marino C, De’donato F, Menne B, Katsouyanni K, Kirchmayer U, Analitis A, Medina-Ramon M, Paldy A, et al. The impact of heat waves on mortality in 9 European cities: results from the EuroHEAT project. Environ Health. 2010;9:37.View ArticlePubMedPubMed CentralGoogle Scholar
- Morabito M, Crisci A, Moriondo M, Profili F, Francesconi P, Trombi G, Bindi M, Gensini GF, Orlandini S. Air temperature-related human health outcomes: current impact and estimations of future risks in Central Italy. Sci Total Environ. 2012;441:28–40.View ArticlePubMedGoogle Scholar
- Anderson GB, Bell ML. Heat waves in the United States: mortality risk during heat waves and effect modification by heat wave characteristics in 43 U.S. communities. Environ Health Perspect. 2011;119:210–8.View ArticlePubMedGoogle Scholar
- Mcgeehin MA, Mirabelli M. The potential impacts of climate variability and change on temperature-related morbidity and mortality in the United States. Environ Health Perspect. 2001;109 Suppl 2:185–9.View ArticlePubMedPubMed CentralGoogle Scholar
- Ng CF, Ueda K, Takeuchi A, Nitta H, Konishi S, Bagrowicz R, Watanabe C, Takami A. Sociogeographic variation in the effects of heat and cold on daily mortality in Japan. J Epidemiol. 2014;24:15–24.View ArticlePubMedGoogle Scholar
- Ma W, Chen R, Kan H. Temperature-related mortality in 17 large Chinese cities: how heat and cold affect mortality in China. Environ Res. 2014;134:127–33.View ArticlePubMedGoogle Scholar
- Clougherty JE. A growing role for gender analysis in air pollution epidemiology. Environ Health Perspect. 2010;118:167–76.View ArticlePubMedGoogle Scholar
- Zhou MG, Wang LJ, Liu T, Zhang YH, Lin HL, Luo Y, Xiao JP, Zeng WL, Zhang YW, Wang XF, et al. Health impact of the 2008 cold spell on mortality in subtropical China: the climate and health impact national assessment study (CHINAs). Environ Health. 2014;13:60.View ArticlePubMedPubMed CentralGoogle Scholar
- Analitis A, Michelozzi P, D’Ippoliti D, De’donato F, Menne B, Matthies F, Atkinson RW, Iniguez C, Basagana X, Schneider A, et al. Effects of heat waves on mortality: effect modification and confounding by air pollutants. Epidemiology. 2014;25:15–22.View ArticlePubMedGoogle Scholar
- Bell ML, O’Neill MS, Ranjit N, Borja-Aburto VH, Cifuentes LA, Gouveia NC. Vulnerability to heat-related mortality in Latin America: a case-crossover study in Sao Paulo, Brazil, Santiago, Chile and Mexico City, Mexico. Int J Epidemiol. 2008;37:796–804.View ArticlePubMedPubMed CentralGoogle Scholar
- Yu W, Guo Y, Ye X, Wang X, Huang C, Pan X, Tong S. The effect of various temperature indicators on different mortality categories in a subtropical city of Brisbane, Australia. Sci Total Environ. 2011;409:3431–7.View ArticlePubMedGoogle Scholar
- Guo Y, Barnett AG, Pan X, Yu W, Tong S. The impact of temperature on mortality in Tianjin, China: a case-crossover design with a distributed lag nonlinear model. Environ Health Perspect. 2011;119:1719–25.View ArticlePubMedPubMed CentralGoogle Scholar
- Yu W, Mengersen K, Wang X, Ye X, Guo Y, Pan X, Tong S. Daily average temperature and mortality among the elderly: a meta-analysis and systematic review of epidemiological evidence. Int J Biometeorol. 2012;56:569–81.View ArticlePubMedGoogle Scholar
- Anderson BG, Bell ML. Weather-related mortality: how heat, cold, and heat waves affect mortality in the United States. Epidemiology. 2009;20:205–13.View ArticlePubMedPubMed CentralGoogle Scholar