Heat-health Action Plans Research Articles

Climate change health challenges – a study on heat health-related adaption measures in Germany

Abstract Problem Increasing extreme heat events of summer 2003, 2010 and 2015 induced a rising impact on heat health morbidity and mortality in Germany. A considerable proportion of urban population is affected by thermal discomfort due to the urban heat island burden during summer, particularly vulnerable people at risk. Concerted action to develop appropriate heat health adaptation measures is needed. Description As part of the National Adaptation Strategy to Climate Change an expert working group published ‘Recommendations for Action for the Preparation of Heat Action Plans’ for Germany in 2017. A first country-wide project had been conducted between 2019 and 2023 which investigated the status and impact of current or planned Heat Health Action Plans (HHAP), and adaptation measures appropriate to protect and prevent human health. As part of this project an online survey was conducted in May/June 2020 on the awareness and degree of use of the 2017 recommendations and the development and implementation of HHAP. Results This survey had been carried out to assess the current state of affairs as well as factors of success and barriers in the development and implementation of HHAP, with a particular focus on municipal environment and health administrations. In total 116 questionnaires had been responded, mainly by participants from the environment sector (53%), and 32% from the public health sector. More than half of the respondents indicated to be aware of the recommendations (very well-known at the federal state level: 90%, at county level known by 43%), which were identified as very helpful by 81%. Respondents from large cities (> 100 000 inhabitants) were main contributors to the study (41 of 81 large cities replied; 34 rural counties responded). Key messages • The 2017 recommendations had been identified and used to start with HHAP. • Decision makers should develop structures for regulations that anchor HHAP as a nationwide instrument to be established timely.

From Pandemic to Heatwave: Digital Strategies for Health Resilience

Abstract Heatwaves threaten public health in the EU, as evidenced by the high heat-related mortality in the summer of 2022. Despite their frequency, European heat-health action plans (HHAPs) largely exclude digital solutions. The COVID-19 pandemic shifted perceptions and use of digital health tools, demonstrating their effectiveness in responding to health crises and providing insights for heatwave management. This work explores the potential of further including digital health interventions into European HHAPs. The objective is to identify adaptable digital strategies to mitigate heatwave health impacts. We started by analyzing WHO’s guidance on the creation of HHAPs, as well as the European Observatory on Health Systems and Policies’ assessment of the four main areas supported by digital health tools during the pandemic. Later, we proposed four main areas where digital health solutions could be efficiently integrated. Each area underwent a rapid literature review to identify digital solutions used during COVID-19, followed by a critical analysis for applicability in heat-health action planning. We identified four areas where the implementation of digital tools should be explored: Communication and Information Dissemination (focusing on raising awareness among vulnerable groups, caregivers, and organizations); Modeling and Forecasting (developing precise forecasts for proactive planning); Health services coordination (among services delivering immediate care during heatwaves); Monitoring and Population Surveillance (implementing strategies to identify and mitigate heat-related risks e.g. among vulnerable populations). Results indicate that digital health solutions from COVID-19 can enhance national HHAPs. Tools for pandemic prevention and response are applicable to extreme weather events. The pandemic’s increased digital usage resulted from policy changes and infrastructure investment - leveraging these advancements could prepare Europe for extreme heat threats. Key messages • Results indicate that digital health solutions from COVID-19 can enhance national HHAPs. Tools for pandemic prevention and response are applicable to extreme weather events. • The pandemic’s increased digital usage resulted from policy changes and infrastructure investment - leveraging these advancements could prepare Europe for extreme heat threats.

Individual level risk factors associated with episodes of heat as recorded within primary care records: a time-stratified case-cross over study

Abstract Background A key recommended action outlined in Heat-Health Action Plans is to identify individuals at risk and deploy targeted interventions, however this is not routinely undertaken. A major contributing factor is a lack of understanding of individual-level risk factors to support an evidence-based approach to targeted prevention. Aim To use electronic health data to identify individual level characteristics associated with increased risk of mortality during heatwaves in England. Methods A time-stratified case-crossover analysis was undertaken of individual-level clinical and socio-environmental (SE) risk factors. Conditional logistic regression was used to characterise associations between temperature and the risk of death on hot days, with analysis stratified by potential risk modifying factors. Results Heat mortality risk was modified by a large range of chronic conditions, with cardio-respiratory, mental health and cognitive function conditions, diabetes and Parkinson’s, all increasing risk. Prescribed medications also increased odds of death during heatwaves. Heat mortality risk was modified by a range of SE determinants of health investigated, with ORs increasing with age; OR differences by sex, ethnicity and living arrangement; an increasing trend in ORs by alcohol intake and body mass index, excluding the obese-3 group. Results suggest the least deprived have the lowest OR and the most deprived have the highest. Conclusions This study has important implications for patient medication management during heat events, incorporating heat-risk considerations into other health policies. The results also provide important evidence on the role of disadvantage in driving the inequitable distribution of climate impacts, and the need for better socio-economic data sets linked to health records. The findings highlight the importance of incorporating an assessment of individual SE circumstances when prioritising patients at highest risk during heat events.

Challenges posed by climate hazards to cardiovascular health and cardiac intensive care: implications for mitigation and adaptation.

Global warming, driven by increased greenhouse gas emissions, has led to unprecedented extreme weather events, contributing to higher morbidity and mortality rates from a variety of health conditions, including cardiovascular disease (CVD). The disruption of multiple planetary boundaries has increased the probability of connected, cascading, and catastrophic disasters with magnified health impacts on vulnerable populations. While the impact of climate change can be manifold, non-optimal air temperatures (NOTs) pose significant health risks from cardiovascular events. Vulnerable populations, especially those with pre-existing CVD, face increased risks of acute cardiovascular events during NOT. Factors such as age, socio-economic status, minority populations, and environmental conditions (especially air pollution) amplify these risks. With rising global surface temperatures, the frequency and intensity of heatwaves and cold spells are expected to increase, emphasizing the need to address their health impacts. The World Health Organization recommends implementing heat-health action plans, which include early warning systems, public education on recognizing heat-related symptoms, and guidelines for adjusting medications during heatwaves. Additionally, intensive care units must be prepared to handle increased patient loads and the specific challenges posed by extreme heat. Comprehensive and proactive adaptation and mitigation strategies with health as a primary consideration and measures to enhance resilience are essential to protect vulnerable populations and reduce the health burden associated with NOTs. The current educational review will explore the impact on cardiovascular events, future health projections, pathophysiology, drug interactions, and intensive care challenges and recommend actions for effective patient care.

Vulnerability to heat-related mortality and the effect of prevention measures: a time-stratified case-crossover study in Switzerland.

Swiss climate scenarios predict increases in the frequency and intensity of extreme heat episodes in the future. For the effective prevention of heat-related mortality, several aspects of the population's vulnerability to heat must be understood on a local level. A nationwide analysis of individual death records was conducted, enabling a more comprehensive understanding than typical heat studies based on aggregated data. A total of 320,306 individual death records from the Swiss National Cohort with precise address information during the warm season (May to September) from 2003-2016 were linked to indoor and outdoor high-resolution daily temperature estimates. A time-stratified case-crossover study combined with distributed lag non-linear models was then performed to assess the temperature-mortality associations for various causes of death and to estimate the potential effect modification of individual characteristics. Additionally, it was explored whether the effect of extreme heat changed over time in regions with and without cantonal heat-health action plans (HHAPs). Using the temperature with the lowest cause-specific mortality risk (minimum mortality temperature) as the reference temperature, extreme heat (defined as ambient daily maximum temperature reaching 33 °C) was associated with a strong increase in all-cause mortality (odds ratio (OR): 1.21, 95% CI: 1.17-1.25) and disease-specific mortality from Alzheimer's disease and dementia (OR: 1.67, 95% CI: 1.48-1.88), COPD (OR: 1.37, 95% CI: 1.12-1.67), diabetes (OR: 1.34, 95% CI: 1.06-1.70), and myocardial infarction (OR: 1.26, 95% CI: 1.10-1.44). Indoor temperatures above 24 °C were found to be critical for mortality. The population most vulnerable to heat included older adults (≥75 years), unmarried individuals, people with a low education level, older women with low neighbourhood socioeconomic position, and men under 75 years old with low socioeconomic position. Overall, the risk of heat-related all-cause mortality in 2009-2016 was lower than that in 2003-2008. The decrease was significantly stronger in the region where cantonal HHAPs were implemented. This study provides important information for planning targeted and effective measures to reduce heat-related health risks in Switzerland. It demonstrates that HHAPs contribute to reducing heat-related mortality, although they may not reach the high-risk population of individuals with low socioeconomic position. Future prevention efforts should also target the less privileged population, including people younger than 75 years.

Multimorbidity and emergency hospitalisations during hot weather

BackgroundPeople with chronic diseases are a commonly listed heat-vulnerable group in heat-health action plans. While prior research identifies multiple health conditions that may increase vulnerability to ambient heat, there is minimal evidence regarding the implications of multimorbidity (two or more chronic diseases). MethodsFrom the statewide hospital registry of Queensland, Australia, we identified people aged ≥15 years who had emergency hospitalisation(s) between March 2004 and April 2016 and previously had 0, 1, 2, or ≥3 of five chronic diseases: cardiovascular disease, diabetes, mental disorders, asthma/COPD, and chronic kidney disease. We conducted time-stratified case-crossover analyses to estimate the odds ratio of hospitalisations associated with ambient heat exposure in people with different numbers, types, and combinations of chronic diseases. Ambient heat exposure was defined as a 5 °C increase in daily mean temperature above the median. FindingsThere were 2,263,427 emergency hospitalisations recorded (48.7% in males and 51.3% in females). When the mean temperature increased, hospitalisation odds increased with chronic disease number, particularly in older persons (≥65 years), males, and non-indigenous people. For instance, in older persons with 0, 1, 2, or ≥3 chronic diseases, the odds ratios associated with ambient heat exposure were 1.00 (95% confidence interval: 0.96, 1.04), 1.06 (1.02, 1.09), 1.08 (1.02, 1.14), and 1.13 (1.07, 1.19), respectively. Among the chronic diseases, chronic kidney disease, and asthma/COPD, either existing alone, together, or in combination with other diseases, were associated with the highest odds of hospitalisations under ambient heat exposure. InterpretationWhile individuals with multimorbidity are considered in heat-health action plans, this study suggests the need to consider specifically examining them as a distinct and vulnerable subgroup. FundingWellcome.

Composition of factors for local heat adaptation measures at the local level in cities of the mid-latitude – An approach for the south-west of Germany

Traditional heat health warning systems focus on severe and extreme heat events at the district or regional level, often overlooking localized risk and protective factors such as healthcare access and urban green spaces. This approach considers less the varying impacts of heat within cities, including the phenomenon of Urban Heat Islands (UHIs) and the diverse needs of different populations. To address these shortcomings, a need for the development of an Urban Heat Health Warning and Information System (UHHWIS) that operates within the framework of Heat Health Action Plans is needed. Such a system integrates national acute heat health warnings with city-specific assessments of UHI effects and other relevant factors. The technical implementation of the UHHWIS involves the calculation and preprocessing of basic factors such as the Normalised Difference Vegetation Index (NDVI), imperviousness, and UHI intensity. Additionally, further factors are assessed, spatially processed, and provided in accordance with Open Geospatial Consortium (OGC) standards. An iso-area analysis is conducted to evaluate the accessibility of protective factors, such as urban green spaces, drinking wells, hospitals, physicians, and pharmacies, based on the city’s road topology. One crucial factor considered in the system is the casting of shadows, which is influenced by both time and location and facilitated through deck.gl. The developed template encompasses all these components into a unified system aimed at protecting vulnerable and risk groups, such as the elderly, through resilient, climate-adapted urban planning. The system provides warnings and information tailored to the urban morphology and prevailing conditions, complemented by a catalogue of potential short- to long-term measures focused on behavioral changes and climate-resilient urban planning strategies. The template can be adapted for use in various European cities, offering valuable insights to decision-makers in city administration for mitigating thermal stress and enhancing resilience against urban heat nowadays and in future.

In situ physiological and behavioural responses of vulnerable populations during an extreme heat event in Montreal, Quebec 2023: a pilot study

Introduction: Extreme heat events (EHE) continue to increase in frequency, intensity, and duration, posing a significant health threat to vulnerable populations. Despite the development of heat-health action plans, heat-related injuries during EHE persist with the majority occurring at-home. Although epidemiological evidence has identified vulnerable populations, limited evidence exists to confirm their physiological and behavioural responses within the natural environment. Objective: The objective was to undertake a pilot study to monitor heat-vulnerable populations before and during an EHE and determine whether differences in physiological strain, subjective sleep quality, thermal perception, and thirst, would be detected during the EHE. Methods: Five participants who identified as a member of at least one heat-vulnerable group (67±5 y, 84.3±18.0 kg) participated in this study which ran throughout the summer months in Montreal, Quebec 2023. Using HeatSuite, a multipoint remote data acquisition platform that captures indoor environmental conditions, participants continuously wore a fitness tracker, completed a daily sleep quality assessment and a short questionnaire 4 times a day to quantify their thermal sensation, thermal comfort, and thirst, and recorded their oral temperature, heart rate, and blood pressure at rest 3 times a day (morning, midday, and evening). An EHE, as defined by Environment Canada, occurred Sept. 5th – 7th (max ambient temperature: 30.6±0.6°C; max humidex: 40.7±0.6), and thus the physiological and behavioural data collected are compared to the 3 preceding days (Sept. 2nd – 4th, PRE; max ambient temperature 27.2±2.3°C; max humidex: 34.0±4.6). Results: While all participants had air-conditioning, mean indoor ambient temperature was slightly higher during the EHE (22.5±0.5°C) than PRE (21.4±0.6°C, P=0.03). Total step count increased during the EHE relative to PRE in 4 of 5 participants (+47±83%). Mean oral temperature was higher during the EHE (37.3±1.0°C) compared to PRE (36.7±0.7°C, p<0.05). Mean heart rate was not different during the EHE (82±8 BPM) relative to PRE (81±7 BPM, P=0.32). Mean blood pressure was not different during PRE compared to during the EHE (P>0.38). Subjective sleep quality was lower during the EHE compared to PRE (p<0.05). Participants reported no difference in thermal discomfort (P=0.12) and sensation (P=0.38), however they reported an increased thirst sensation (P=0.03) during the EHE. Conclusion: This pilot study was successful at monitoring physiological and behavioural responses in situ of heat-vulnerable individuals during an EHE. The results suggest that the EHE reduced sleep quality, increased thirst and thermal sensations, resulted in a higher oral temperature, and that participants were more active during the EHE relative to the 3 preceding days. This research is supported by Dr. Ravanelli’s New Frontiers in Research Fund (NFRFR-2021-00247). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Modeling the Normalized Urban Heat Island for the City of Karlsruhe by Linking Urban Morphology and Green Infrastructure

Citizens in urban areas are affected by the urban heat island (UHI) effect, resulting in increased thermal heat compared to rural areas. This threat is exacerbated by global climate change. Therefore, it is necessary to assess human thermal comfort and risk for decision making. This is important for planners (climate resilience), the health sector (information for vulnerable people), tourism, urban designers (aesthetics), and building architects. Urban structures modify local meteorological parameters and thus human thermal comfort at the microscale. Knowledge of the pattern of a city’s UHI is typically limited. Based on previous research, generalized additive models (GAMs) were built to predict the spatial pattern of the UHI in the city of Karlsruhe. The models were trained with administrative, remotely sensed, and land use and land cover geodata, and validated with measurements in Freiburg. This identified the hot and cold spots and the need for further urban planning in the city. The model had some limitations regarding water bodies and anthropogenic heat production, but it was well suited for applications in mid-latitude cities which are not topographically characterized. The model can potentially be used for other cities (e.g., in heat health action plans) as the training data are freely available.

Smart heat-health action plans: A programmatic, progressive and dynamic framework to address urban overheating

Cities stand at the focal point of vulnerability to heat waves (HWs) as they threaten urban livability and sustainability. National, regional, and local heat-health action plans (HHAPs) are vital for combating HWs and are increasingly crucial as adaptation measures to extreme heat. The present article highlights the most recent development on the working mechanism of HHAPs, its contemporary challenges, barriers to it and a range of operational heat management and planning strategies. It introduces the concept of 'smartness' to the existing mechanism of HHAPs which holds a significant potential to be intelligent, explicit and dynamic to address the growing and multifaceted impacts of extreme heat. It emphasizes urgent priorities including long-term heat planning, multisectoral heat-early warning systems, building urban heat resilience and recommends the application of eight core elements endorsed by the World Health Organization (WHO) for effective implementation of HHAPs. Collaboration among meteorological, epidemiological, public health, and urban planning experts is essential for addressing the multidimensional challenges of extreme heat.

Identifying heat thresholds for South Africa towards the development of a heat-health warning system.

Exposure to heatwaves may result in adverse human health impacts. Heat alerts in South Africa are currently based on defined temperature-fixed threshold values for large towns and cities. However, heat-health warning systems (HHWS) should incorporate metrics that have been shown to be effective predictors of negative heat-related health outcomes. This study contributes to the development of a HHWS for South Africa that can potentially minimize heat-related mortality. Distributed lag nonlinear models (DLNM) were used to assess the association between maximum and minimum temperature and diurnal temperature range (DTR) and population-adjusted mortality during summer months, and the effects were presented as incidence rate ratios (IRR). District-level thresholds for the best predictor from these three metrics were estimated with threshold regression. The mortality dataset contained records of daily registered deaths (n = 8,476,532) from 1997 to 2013 and data for the temperature indices were for the same period. Maximum temperature appeared to be the most statistically significant predictor of all-cause mortality with strong associations observed in 40 out of 52 districts. Maximum temperature was associated with increased risk of mortality in all but three of the districts. Our results also found that heat-related mortality was influenced by regional climate because the spatial distribution of the thresholds varied according to the climate zones across the country. On average, districts located in the hot, arid interior provinces of the Northern Cape and North West experienced some of the highest thresholds compared to districts located in temperate interior or coastal provinces. As the effects of climate change become more significant, population exposure to heat is increasing. Therefore, evidence-based HHWS are required to reduce heat-related mortality and morbidity. The exceedance of the maximum temperature thresholds provided in this study could be used to issue heat alerts as part of effective heat health action plans.

Highly Heterogeneous Heat‐Related Health Impacts in China and Implications for Sustainable Urban Heat Governance

AbstractUnderstanding heat‐related impacts is crucial to improving public awareness of addressing urban heat challenges and enabling decision makers to mainstream heat action plans. This study explores heat‐related physiological and psychological impacts, symptoms, and demographic determinants based on 4210 questionnaires across nine large Chinese cities, including Chengdu, Chongqing, Guangzhou, Hangzhou, Nanchang, Nanjing, Shanghai, Shenyang, and Xi'an in August 2020. The results indicate that heat‐related psychological impacts are equally severe as physiological impacts. Chongqing is under the most severe heat‐related health impact on both the physiological and psychological aspects. Skin heat damage (SKI), digestive system illnesses (DIG), respiratory illnesses (RES), and cardiovascular illnesses (CAR) are prominent physiological illnesses in all cities, while emotional irritability (EMO), easy to lose control temper (EAS), low mood (LOW), and insomnia (INS) are prominent psychological symptoms. Chongqing and Guangzhou are the most vulnerable cities in terms of physiological and psychological symptoms. Chengdu, Hangzhou, Nanjing, and Shanghai are more resilient in terms of physiological symptoms, whereas Chengdu, Hangzhou, and Shanghai are more resistant to psychological symptoms. Heat‐related health impacts, symptoms, and demographic determinants are spatially heterogeneous. The elderly and patients are more vulnerable, while such a conclusion is not always true. The spatial heterogeneity of heat‐related physiological and psychological impacts, symptoms, and drivers highlights the significance of developing city‐specific heat health action plans.

Heat health action plans: a European perspective

Abstract Background With average temperatures on the rise, collaboration of European countries regarding climate change adaptation and climate resilience of their health systems is becoming an important lever for protecting older people, while recognising the diversity of older people's living environments, socio-economic conditions, as well as intersectionalities with gender and race within different subgroups of older people. Heat-health action plans (HHAPs) are one example where a common European framework (e.g. within the WHO-European region) may guide general measures, yet without being able to account for context-specific, geographic and population-specific conditions in each country, or at the subnational level. Objective Along WHO-Europe's framework for HHAP, this presentation aims to provide an overview of the core elements in place at the European level that public health officials can utilise to protect older people from heat and/or prevent heat impacts on older people, and will highlight the barriers and enablers for action. The presentation will also examine current levers and assets that exist at European, sub-national and local/municipal level to strengthen responses. Results Using examples from across European countries, the presentation summarises the current strategic and policy context framing responses to heat health for older people and will highlight what has worked well and where further work needs to be done. The presentation will also inspire dialogue among attendees, sharing knowledge from their countries and contexts. Conclusions A more targeted approach leveraging existing strategies and assets is needed to support policy-makers in implementing interventions to protect older people within the context of current HHAPs at different governance levels.

Heat in Germany: Health risks and preventive measures.

Climate change has already led to a significant temperature increase in Germany. The average temperature in the past decade was approximately 2°C above the pre-industrial level and eight of the ten hottest summers since the beginning of systematic weather records in 1881 were recorded in the last 30 years. Based on a selective literature search and authors' own results, the article summarises the current state of knowledge on heat and its health impacts for Germany, addresses adaptation measures, and gives an outlook on implementation and research questions. Heat can aggravate pre-existing conditions such as diseases of the cardiovascular system, the respiratory tract, or the kidneys and trigger potentially harmful side effects for numerous medications. A significant increase in mortality is regularly observed during heat events. Previous approaches to mitigate the health impact of high temperatures include, for example, the heat alerts of the German Meteorological Service and recommendations for the preparation of heat-health action plans. Evidence on health impacts of heat and awareness of the need for heat-related health protection have grown in recent years, but there is still a need for further action and research.

Assessment of short-term heat effects on cardiovascular mortality and vulnerability factors using small area data in Europe

BackgroundShort-term associations between heat and cardiovascular disease (CVD) mortality have been examined mostly in large cities. However, different vulnerability and exposure levels may contribute to spatial heterogeneity. This study assessed heat effects on CVD mortality and potential vulnerability factors using data from three European countries, including urban and rural settings. MethodsWe collected daily counts of CVD deaths aggregated at the small-area level in Norway (small-area level: municipality), England and Wales (lower super output areas), and Germany (district) during the warm season (May-September) from 1996 to 2018. Daily mean air temperatures estimated by spatial–temporal models were assigned to each small area. Within each country, we applied area-specific Quasi-Poisson regression using distributed lag nonlinear models to examine the heat effects at lag 0–1 days. The area-specific estimates were pooled by random-effects meta-analysis to derive country-specific and overall heat effects. We examined individual- and area-level heat vulnerability factors by subgroup analyses and meta-regression, respectively. ResultsWe included 2.84 million CVD deaths in analyses. For an increase in temperature from the 75th to the 99th percentile, the pooled relative risk (RR) for CVD mortality was 1.14 (95% CI: 1.03, 1.26), with the country-specific RRs ranging from 1.04 (1.00, 1.09) in Norway to 1.24 (1.23, 1.26) in Germany. Heat effects were stronger among women [RRs (95% CIs) for women and men: 1.18 (1.08, 1.28) vs. 1.12 (1.00, 1.24)]. Greater heat vulnerability was observed in areas with high population density, high degree of urbanization, low green coverage, and high levels of fine particulate matter. ConclusionThis study provides evidence for the heat effects on CVD mortality in European countries using high-resolution data from both urban and rural areas. Besides, we identified individual- and area-level heat vulnerability factors. Our findings may facilitate the development of heat-health action plans to increase resilience to climate change.

The association between high ambient temperature and risk of hospitalization: a time-series study in eight ecological regions in Vietnam

Viet Nam is among the countries most threatened by and vulnerable to climate change and extreme weather events. However, research on the temperature-morbidity relationship at the national scale has been scarce. This study aimed to assess the impact of high temperatures on the risk of hospital admissions for all causes and heat-sensitive diseases across eight ecological regions in Vietnam. The study utilized a longitudinal dataset that included hospitalization and meteorological data from eight provinces representing eight regions in Vietnam. A time series analysis was applied using the generalized linear and distributed lag models with a quasi-Poisson family to examine the temperature-hospitalization association in each province. A random-effects meta-analysis was used to calculate the pooled estimate of risk for the national scale. The country-level pooled effects (%, [95% CI]) indicated that a 1 °C increase above the threshold temperature (19 °C) increased the hospitalization risk for all causes and infectious diseases by 0.8% [0.4%–1.2%] and 2.4% [1.02%–1.03%], respectively at lag 0–3 d. The effects of heat on respiratory diseases and mental health disorders were not significant. At the regional level, the association varied across eight regions, of which the Northern parts tended to have a higher risk than the Southern. This is among very few national-scale studies assessing hospitalization risk associated with high temperatures across eight ecological regions of Vietnam. These findings would be useful for developing evidence-based heat-health action plans.

Heat in German cities: a study on existing and planned measures to protect human health

AimExtreme heat events caused by climate change continue to increase in frequency, duration, and intensity. People living in cities in particular are exposed to heat as a result of the urban heat island effect. Although negative effects can be mitigated by heat health action plans (HHAPs), it remains unknown how many German cities have implemented such plans or other measures to reduce the health risks from heat. Therefore, this study surveyed the status of planned or published HHAPs and measures in German cities.Subject and methodsApproximately 10% of German cities with the greatest population density were sampled for the study (n = 70 cities). A frequency analysis of city concepts and city webpages was conducted to determine whether cities have already introduced concepts for climate adaptation, climate protection or an HHAP, and which measures are planned in detail.ResultsFifty-one cities have implemented measures to protect health from heat events. Forty-one cities integrated such measures into concepts, and only one city formulated an HHAP. Large cities in particular published measures. Long-term measures proved most common, for example, improved building envelope insulation and urban greening. Other than advice on individual behavior, hardly any acute heat health measures are being taken.ConclusionPublic health authorities can play an active role in communicating the health risks of heat and implementing HHAPs. To this end, the health risks of climate change need to be addressed consistently by all policy fields in Germany. There is also a need for further research in the evaluation of measures and HHAPs.

Climate change scenarios in use: Heat stress in Switzerland

Under hot conditions the human body is able to regulate its core temperature via sweat evaporation, but this ability is reduced when air humidity is high. These conditions of high temperature and high humidity invoke heat stress which is a major problem for humans, in particular for vulnerable groups of the population and people under physical stress (e.g. heavy duty work without appropriate cooling systems). It is generally expected that the frequency, duration and magnitude of such unfavorable conditions will increase with further climate warming. In this respect, climate services play a crucial role by putting together climatological information and adaptation solutions to reduce future heat stress. We here assess the recently developed CH2018 scenarios for Switzerland (https://www.climate-scenarios.ch) in terms of heat stress conditions including their future projections. For this purpose, we characterize future extreme heat conditions with the use of climate analogs. By doing so, we attempt to produce more accessible climate information which might foster the use and understanding of regional-scale climate scenarios.Here heat stress is expressed through the Wet Bulb Temperature (TW), which is a relatively simple proxy for heat stress on the human body and which depends non-linearly on temperature and humidity. It is assessed in terms of single-day events and heat stress spells. Projections based on the CH2018 scenarios indicate increasing heat stress over Switzerland, which is accentuated towards the end of the century. High heat stress conditions might be about 3–5 times more frequent for an emission scenario without mitigation (RCP 8.5) than for the mitigation scenario (RCP 2.6) by the end of the 21st century. The projected increase of heat stress results in more and longer heat stress spells, thus highlighting the importance of timely and precise prevention strategies in the context of heat-health action plans. Spatial climate analogs based on heat stress spells in Switzerland greatly vary depending on the emission scenario and are found in Central Europe under a mitigation scenario and in southern Europe under unmitigated warming.

A Step to Develop Heat-Health Action Plan: Assessing Heat Waves’ Impacts on Mortality

Climate change is one of the biggest health threats facing humanity and can directly affect human health through heat waves. This study aims to evaluate excess deaths during heat waves between the summer months of 2004 and 2017 in Istanbul and to determine a definition of heat waves that can be used in the development of an early warning system, a part of prospective urban heat-health action plans. In this study, heat waves were determined using the Excess Heat Factor, an index based on a three-day-averaged daily mean temperature. The death rates during heat waves and non-heat wave days of the summer months were compared with a Z test of the difference of natural logarithms. Thirty heat waves were recorded in Istanbul during the summer months of 2004–2017. In 67% of the heat waves, the death rate was significantly higher than the reference period and 4281 excess deaths were recorded. The mortality risk was especially higher during heat waves of higher intensity. The study showed an excess risk of mortality during heat waves in Istanbul, and the findings suggest that the Excess Heat Factor could be an appropriate tool for an early warning system in Istanbul.

The role of public health services in implementing heat health action plans in Germany

Abstract Background The rise in extreme heat periods is a major public health challenge of climate change and the World Health Organization therefore recommends the implementation of heat health action plans (HHAPs). In Germany, HHAPs are not implemented in a comprehensive manner nor nationwide. Public health authorities have been identified as key actors with regards to heat and health. This study aims at assessing the role of public health services in the implementation of HHAPs in Germany. Methods First, a review of the scientific and grey literature on the role of public health services in heat adaptation in Europe was conducted. Second, a policy document analysis of the legislation of Germany's federal states for public health services and their potential role in the implementation of HHAPs was carried out. Finally, semi-structured interviews with selected experts from multiple sectors at the local, federal and national level on their perception of the role of public health services in the implementation of HHAPs in Germany were undertaken. Results Preliminary findings show that the legal framework for public health services in the different federal states addresses environmental health and civil protection to varying extents, but that climate change-specific health risks are barely mentioned. The expert interviews revealed perceived barriers for the public health services to implement HHAPs, notably with regards to personnel (e.g. competencies, time), organizational structures (e.g. financial resources, administrative structures, legal mandates) and competing other tasks (e.g. COVID-19 response). Facilitators included motivated individuals, funding opportunities for cross-sectoral collaboration and political support. Conclusions The role of public health services in HHAP implementation in Germany varies widely between the different geographic settings and is influenced by several factors at the individual, organizational and political level. Key messages