Yao Wu, Monash University
Bo Wen, Monash University
Shanshan Li, Monash UniversityFollow
Antonio Gasparrini, London School of Hygiene & Tropical Medicine
Shilu Tong, Shanghai Jiao Tong University
Ala Overcenco, Labour and Social Protection of the Republic of Moldova
Aleš Urban, Czech Academy of Sciences
Alexandra Schneider, German Research Center for Environmental Health
Alireza Entezari, Monash University
Ana Maria Vicedo-Cabrera, London School of Hygiene & Tropical Medicine
Antonella Zanobetti, Harvard University
Antonis Analitis, National and Kapodistrian University of Athens
Ariana Zeka, Brunel University
Aurelio Tobias, Spanish Council for Scientific Research
Barrack Alahmad, Harvard University
Ben Armstrong, London School of Hygiene & Tropical Medicine
Bertil Forsberg, Umeå University
Carmen Íñiguez, Universitat de València
Caroline Ameling, Centre for Sustainability and Environmental Health, Bilthoven
César De la Cruz Valencia, National Institute of Public Health, Mexico
Chrisofer Åström, Umeå University
Danny Houthuijs, Centre for Sustainability and Environmental Health, Bilthoven
Do Van Dung, University of Medicine and Pharmacy at Ho Chi Minh City
Dominic Royé, CIBER de Epidemiología y Salud Pública (CIBERESP), Madrid
Ene Indermitte, University of Tartu
Eric Lavigne, University of Ottawa
Fatemeh Mayvaneh, Hakim Sabzevari University
Fiorella Acquaotta, University of Turin
Francesca de’Donato, Lazio Regional Health Service, Rome
Francesco Sera, University of Florence
Gabriel Carrasco-Escobar, Universidad Peruana Cayetano Heredia, Lima
Haidong Kan, Fudan University, Shanghai
Hans Orru, University of Tartu
Ho Kim, Seoul National University
Iulian-Horia Holobaca, Babeş-Bolyai University
Jan Kyselý, Czech Academy of Sciences
Joana Madureira, Universidade do Porto
Joel Schwartz, Harvard University
Klea Katsouyanni, National and Kapodistrian University of Athens
Magali Hurtado-Diaz, National Institute of Public Health, Mexico
Martina S. Ragettli, University of Basel
Masahiro Hashizume, Tokyo University
Mathilde Pascal, Santé Publique France
Micheline de Sousa Zanotti Stagliorio Coélho, University of São Paulo
Noah Scovronick, Emory University, Atlanta
Paola Michelozzi, Lazio Regional Health Service
Patrick J. Goodman, Technological University DublinFollow
Paulo Hilario Nascimento Saldiva, INSPER, São Paulo
Rosana Abrutzky, Universidad de Buenos Aires
Samuel Osorio, University of São Paulo
Tran Ngoc Dang, University of Medicine and Pharmacy at Ho Chi Minh City
Valentina Colistro, Universidad de Montevideo
Veronika Huber, LMU Munich
Whanhee Lee, Yale University
Xerxes Seposo, Nagasaki University
Yasushi Honda, National Institute for Environmental Studies, Tsukuba
Michelle L. Bell, Yale University
Yuming Guo, Monash UniversityFollow

Document Type



Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence




Studies have investigated the effects of heat and temperature variability (TV) on mortality. However, few assessed whether TV modifies the heat-mortality association. Data on daily temperature and mortality in the warm season were collected from 717 locations across 36 countries. TV was calculated as the standard deviation of the average of the same and previous days’ minimum and maximum temperatures. We used location-specific quasi-Poisson regression models with an interaction term between the cross-basis term for mean temperature and quartiles of TV to obtain heat-mortality associations under each quartile of TV, and then pooled estimates at the country, regional, and global levels. Results show the increased risk in heat-related mortality with increments in TV, accounting for 0.70% (95% confidence interval [CI]: −0.33 to 1.69), 1.34% (95% CI: −0.14 to 2.73), 1.99% (95% CI: 0.29–3.57), and 2.73% (95% CI: 0.76–4.50) of total deaths for Q1–Q4 (first quartile–fourth quartile) of TV. The modification effects of TV varied geographically. Central Europe had the highest attributable fractions (AFs), corresponding to 7.68% (95% CI: 5.25–9.89) of total deaths for Q4 of TV, while the lowest AFs were observed in North America, with the values for Q4 of 1.74% (95% CI: −0.09 to 3.39). TV had a significant modification effect on the heat-mortality association, causing a higher heat-related mortality burden with increments of TV. Implementing targeted strategies against heat exposure and fluctuant temperatures simultaneously would benefit public health.



This study was supported by the Australian Research Council (DP210102076) and the Australian National Health and Medical Research Council (APP2000581). Y.W and B.W. were supported by the China Scholarship Council (nos. 202006010044 and 202006010043); S.L. was supported by an Emerging Leader Fellowship of the Australian National Health and Medical Research Council (no. APP2009866); Y.G. was supported by Career Development Fellowship (no. APP1163693) and Leader Fellowship (no. APP2008813) of the Australian National Health and Medical Research Council; J.K. and A.U. were supported by the Czech Science Foundation (project no. 20–28560S); N.S. was supported by the National Institute of Environmental Health Sciences-funded HERCULES Center (no. P30ES019776); Y.H. was supported by the Environment Research and Technology Development Fund (JPMEERF15S11412) of the Environmental Restoration and Conservation Agency; M.d.S.Z.S.C. and P.H.N.S. were supported by the São Paulo Research Foundation (FAPESP); H.O. and E.I. were supported by the Estonian Ministry of Education and Research (IUT34–17); J.M. was supported by a fellowship of Fundação para a Ciência e a Tecnlogia (SFRH/BPD/115112/2016); A.G. and F.S. were supported by the Medical Research Council UK (grant ID MR/R013349/1), the Natural Environment Research Council UK (grant ID NE/R009384/1), and the EU’s Horizon 2020 project, Exhaustion (grant ID 820655); A.S. and F.d.D. were supported by the EU’s Horizon 2020 project, Exhaustion (grant ID 820655); V.H. was supported by the Spanish Ministry of Economy, Industry and Competitiveness (grant ID PCIN-2017–046); and A.T. by MCIN/AEI/10.13039/501100011033 (grant CEX2018-000794-S). Statistics South Africa kindly provided the mortality data, but had no other role in the study.