Heat Health Prevention Measures and Adaptation in Older Populations-A Systematic Review

Community-based heat adaptation interventions for improving heat literacy, behaviours, and health outcomes: a systematic review

Anthropogenic climate change, resulting in a continuous rise of global temperature, has detrimental effects on human health, particularly among vulnerable populations, such as individuals with low income, older adults, and people with pre-existing health conditions. To reduce the heat-related health consequences, effective interventions targeting community members, especially vulnerable populations, are paramount. This systematic review aims to identify and evaluate the effectiveness of community-based heat adaptation behavioural interventions aimed at improving heat literacy, promoting adaptive behaviours, and enhancing health outcomes amid rising global temperatures. In this systematic review, peer-reviewed English-language articles focused on community-based heat adaptation intervention studies published in PubMed, MEDLINE via Ovid, Embase, CINAHL, Scopus, and Web of Science from database inception to Jan 1, 2024, were retrieved and reported according to the PRISMA 2020 guidelines. The quality of the articles was evaluated with the use of a mixed-methods appraisal tool. The analysis synthesised intervention effectiveness across multiple outcome domains measurable at both individual and household levels, identified key factors influencing successful implementation, and highlighted areas for future research. The initial search yielded 1266 articles, of which ten were finally included. The majority of the included studies (n=7) were from high-income countries. Most intervention modules focused on preventive measures during heat exposure, whereas only a few addressed information on disease mechanisms, risk factors, and monitoring environmental changes. Although most studies reported significant improvements in heat literacy and a reduction in heat-related symptoms, the evidence for behavioural changes and health outcomes was mixed. Our review reveals methodological shortcomings, as none of the included studies incorporated heat literacy frameworks, behavioural theory, or participatory approaches to include community input throughout the research. Our findings highlight the need for a comprehensive approach that incorporates frameworks to enhance intervention effectiveness and improve public health resilience amid rising global temperatures. Culturally appropriate community-led interventions and integration of digital tools are promising avenues for increasing uptake of interventions. This study is registered with PROSPERO (CRD42024514188).

Impact of Depression on Activation and Summer Heat Adaptation in Older Adults With Cardiovascular Concerns: Empirical Research Quantitative

AIM

To investigate the effects of depression on patient activation and summer heat adaptation, considering important contributory factors in older adults with increased cardiovascular health concerns on extremely hot days.

DESIGN

Cross-sectional study adhering to the STROBE guidelines.

METHODS

Between July and August 2020, a questionnaire survey was administered to 245 older adults at increased risk of cardiovascular diseases in rural areas. Data were collected utilising validated and reliable tools to assess patient activation, depression, summer heat adaptation, frailty, physical activity and other health-related characteristics. Hierarchical regression, mediation and path analyses were conducted to examine the association between activation, depression and summer heat adaptation, while controlling for covariates.

RESULTS

Most participants exhibited the lowest level of activation (75.1%) and a low/moderate level of summer heat adaptation (80.4%). Depression negatively affected activation (β = -0.247), while its indirect effect on patient activation through summer heat adaptation was insignificant (p > 0.05). Education (β = 0.380) and a family history of cardiovascular disease (β = 0.121) positively influenced activation, while alcohol consumption had a negative influence (β = -0.219). When integrating the influence of these three contributory factors, the associative relationship between depression and activation through summer heat adaptation demonstrated a good model fit (chi-square = 8.944, p > 0.05; comparative fit index = 0.987; root mean square error of approximation = 0.045).

CONCLUSION

Improving older adults' activation for self-managing chronic conditions in summer requires tackling depression, enhancing heat adaptation and addressing concerns related to lack of education and alcohol consumption.

PATIENT OR PUBLIC CONTRIBUTION

Patients with cardiovascular diseases were involved in piloting the questionnaire and provided examples to address older adults' concerns related to self-management and heat adaptation.

Intersecting Risk: Heat and Substance Use in Rural Communities

BACKGROUND

Extreme heat has a direct impact on health and can exacerbate substance use. Rural communities are at high risk given higher rates of hospitalizations for heat related illness and the disproportionate effects of substance use. This commentary explores the connection between heat and substance in rural communities and proposes recommendations within the span of policy, research and practice that can be tailored to fit the local rural context.

CONCLUSIONS/IMPORTANCE

If implemented, comprehensive approaches such as Promoting of Local Infrastructure and Safe Spaces, Addressing Structural Health Inequities, Developing Workforce, Developing and Evaluate Public Health Communication Strategies, Engaging the Community in Developing Research, Education and Awareness, and Harm Reduction can lead to systemic changes that will greatly improve the health outcomes of rural communities.

Adapting to heat-health vulnerability in temperate climates: current adaptation and mitigation responses and future predictions in Aotearoa New Zealand

INTRODUCTION

Climate change is raising global temperatures, leading to more extreme heat events, even in temperate climates like Aotearoa|New Zealand (A|NZ). The impact of rising temperatures and the adequacy of planning measures remain underexplored. This paper highlights A|NZ's anticipated heat-health challenges by analyzing vulnerable populations and assessing current response systems, thereby reinforcing the need for system-level redress, mitigation and adaptation.

CONTENT

A scoping review examined the impact of heat and existing mitigation and adaptation responses for vulnerable populations in temperate regions, with a focus on A|NZ. Additionally, temperature trend analysis was conducted for current and projected trends using Climate CHIP for six major heat-affected cities in A|NZ to assess the recognition of heat as a societal concern.

SUMMARY AND OUTLOOK

The review identified mitigation and adaptation strategies for existing vulnerable groups and discovered other potential vulnerable groups in A|NZ, including Indigenous people (Māori), Pacific communities, low-income groups, migrants, and visitors. Temperature trends show an increasing pattern, suggesting heightened future heat-related impacts on these populations. This review reveals A|NZ's growing vulnerability to rising temperatures, particularly among high-risk groups, and calls for stronger mitigation and adaptation strategies to address future heat-health risks.

The impact of nursing sustainable prevention program on heat strain among agricultural elderly workers in the context of climate change

BACKGROUND

This study assesses a geriatric nursing-led sustainable heat prevention program for elderly agricultural workers. It targets those aged 60 and above, addressing the heightened risk of heat strain in the era of climate change.

METHODS

A community-based quasi-experimental design involved 120 elderly agricultural workers, divided into intervention and control groups. The program, spanning three months, included education on hydration, rest, protective clothing, and recognition of heat-related illnesses.

RESULTS

The intervention led by geriatric nursing professionals showed significant improvements in heat strain metrics. The Heat Strain Score Index (HSSI) and the Observational-Perceptual Heat Strain Risk Assessment (OPHSRA) Index indicated increased safety levels and reduced risk categories among participants.

CONCLUSIONS

The study demonstrates the effectiveness of a geriatric nursing-led, tailored prevention program in reducing heat strain among elderly agricultural workers. It highlights the crucial role of nursing in adapting healthcare practices to the challenges posed by climate change.

TRIAL REGISTRATION

ClinicalTrials.gov, ID NCT06192069 retrospectively registered.

Heat and Cardiovascular Mortality: An Epidemiological Perspective

As global temperatures rise, extreme heat events are projected to become more frequent and intense. Extreme heat causes a wide range of health effects, including an overall increase in morbidity and mortality. It is important to note that while there is sufficient epidemiological evidence for heat-related increases in all-cause mortality, evidence on the association between heat and cause-specific deaths such as cardiovascular disease (CVD) mortality (and its more specific causes) is limited, with inconsistent findings. Existing systematic reviews and meta-analyses of epidemiological studies on heat and CVD mortality have summarized the available evidence. However, the target audience of such reviews is mainly limited to the specific field of environmental epidemiology. This overarching perspective aims to provide health professionals with a comprehensive overview of recent epidemiological evidence of how extreme heat is associated with CVD mortality. The rationale behind this broad perspective is that a better understanding of the effect of extreme heat on CVD mortality will help CVD health professionals optimize their plans to adapt to the changes brought about by climate change and heat events. To policymakers, this perspective would help formulate targeted mitigation, strengthen early warning systems, and develop better adaptation strategies. Despite the heterogeneity in evidence worldwide, due in part to different climatic conditions and population dynamics, there is a clear link between heat and CVD mortality. The risk has often been found to be higher in vulnerable subgroups, including older people, people with preexisting conditions, and the socioeconomically deprived. This perspective also highlights the lack of evidence from low- and middle-income countries and focuses on cause-specific CVD deaths. In addition, the perspective highlights the temporal changes in heat-related CVD deaths as well as the interactive effect of heat with other environmental factors and the potential biological pathways. Importantly, these various aspects of epidemiological studies have never been fully investigated and, therefore, the true extent of the impact of heat on CVD deaths remains largely unknown. Furthermore, this perspective also highlights the research gaps in epidemiological studies and the potential solutions to generate more robust evidence on the future consequences of heat on CVD deaths.

The impact of extreme heat on older regional and rural Australians: A systematic review

INTRODUCTION

Extreme heat causes a major health burden, especially for older Australians.

OBJECTIVE

To assess the impact of extreme heat on older regional and rural Australians, including clinical presentations, social implications, and health-seeking behaviours and adaptations.

DESIGN

A systematic review and narrative synthesis.

FINDINGS

Ten articles were included in the review with research on this topic limited. Extreme heat causes an increase in mortality and ambulance dispatches for older rural Australians. Social connectedness is negatively affected by extreme heat due to cancellation of events and individuals becoming housebound. Air conditioning is the main cooling mechanism used, although cost is a major concern. Despite this, older rural populations display a depth of knowledge regarding practical behavioural responses to adapt to extreme heat. Studies show older rural Australians do not consider extreme heat to be a threat to health.

DISCUSSION

Further research needs to examine the role extreme heat may play in contributing to experiences of loneliness. Air conditioning cannot be the ultimate solution in responding to extreme heat due to cost and increased carbon emissions. The low-risk perception of extreme heat for older rural people may inform effective heat health warnings and effective use of primary health care in heat-health education. Listening to First Nations knowledge in dealing with heat may provide a powerful mechanism in which to protect health.

CONCLUSION

The extensive health effects of extreme heat highlights the necessity of further research and strengthening of services in preparation for an ageing rural population enduring climate change.

How do urban green spaces influence heat-related mortality in elderly? A realist synthesis

BACKGROUND

An important consequence of climate change for urban health is heat-related mortality. Vulnerable groups, especially elderly, will be the most affected. A solution put forward in many reports and policy documents is the introduction or expansion of urban green spaces. While they have a proven effect in decreasing the ambient temperature and reducing heat related mortality, the causal pathways are far from clear. Moreover, results vary for different contexts, population types and characteristics of green spaces as they are 'complex systems thrusted into complex systems'. To our knowledge, there is no systematic synthesis of the literature that examines the mechanisms by which and the circumstances under which green spaces work to decrease heat-related mortality for elderly.

METHODS

We performed a realist synthesis- a theory-driven review method- to develop a complexity- and context-sensitive program theory. As a first step, a causal loop diagram was constructed which describes the possible pathways through which urban green spaces influence heat-related mortality in elderly. In a second step, one of the pathways - how they may lead to a reduction of heat-related mortality by increasing social capital - was further explored for underlying mechanisms, the context in which they work and the differentiated patterns of outcomes they generate. Literature was searched for evidence supporting or contradicting the initial programme theory, resulting in a refined theory.

RESULTS

Results show how urban green space can impact on heat-related mortality in elderly by its influence on their exposure to outdoor and indoor heat, by improving their resilience as well as by affecting their access to treatment. Urban green spaces and their interactions with social capital affect the access to health information, social support, and the capacity for effective lobbying. Several mechanisms help to explain these observed demi-regularities, among others perceived behavioural control, perceived usefulness, receptiveness, ontological security, and self-interest. If and how they are triggered depends on the characteristics of the urban green space, the population, and other contextual factors.

CONCLUSION

Looking into the impact of urban green spaces on heat-related mortality in elderly, researchers and policy makers should take interest in the role of social capital.

Changes in tropospheric air quality related to the protection of stratospheric ozone in a changing climate

Ultraviolet (UV) radiation drives the net production of tropospheric ozone (O3) and a large fraction of particulate matter (PM) including sulfate, nitrate, and secondary organic aerosols. Ground-level O3 and PM are detrimental to human health, leading to several million premature deaths per year globally, and have adverse effects on plants and the yields of crops. The Montreal Protocol has prevented large increases in UV radiation that would have had major impacts on air quality. Future scenarios in which stratospheric O3 returns to 1980 values or even exceeds them (the so-called super-recovery) will tend to ameliorate urban ground-level O3 slightly but worsen it in rural areas. Furthermore, recovery of stratospheric O3 is expected to increase the amount of O3 transported into the troposphere by meteorological processes that are sensitive to climate change. UV radiation also generates hydroxyl radicals (OH) that control the amounts of many environmentally important chemicals in the atmosphere including some greenhouse gases, e.g., methane (CH4), and some short-lived ozone-depleting substances (ODSs). Recent modeling studies have shown that the increases in UV radiation associated with the depletion of stratospheric ozone over 1980-2020 have contributed a small increase (~ 3%) to the globally averaged concentrations of OH. Replacements for ODSs include chemicals that react with OH radicals, hence preventing the transport of these chemicals to the stratosphere. Some of these chemicals, e.g., hydrofluorocarbons that are currently being phased out, and hydrofluoroolefins now used increasingly, decompose into products whose fate in the environment warrants further investigation. One such product, trifluoroacetic acid (TFA), has no obvious pathway of degradation and might accumulate in some water bodies, but is unlikely to cause adverse effects out to 2100.

Perception of extreme hot weather and the corresponding adaptations among older adults and service providers-A qualitative study in Hong Kong

Background

Extreme hot weather events are happening with increasing frequency, intensity and duration in Hong Kong. Heat stress is related to higher risk of mortality and morbidity, with older adults being particularly vulnerable. It is not clear whether and how the older adults perceive the increasingly hot weather as a health threat, and whether community service providers are aware and prepared for such future climate scenario.

Methods

We conducted semi-structure interviews with 46 older adults, 18 staff members of community service providers and two district councilors of Tai Po, a north-eastern residential district of Hong Kong. Transcribed data were analyzed using thematic analysis until data saturation was reached.

Results

It was agreed upon among the older adult participants that the weather in recent years has become increasingly hot and this led to some health and social problems for them, although some participants perceived that hot weather did not have any impact in their daily lives and they were not vulnerable. The community service providers and district councilors reported that there is a lack of relevant services in the community to support the older adults in hot weather; and there is generally a lack of public education regarding the heat-health issue.

Conclusions

Heatwaves are affecting older adults' health in Hong Kong. Yet, discussions and education effort regarding the heat-health issue in the public domain remain scarce. Multilateral efforts are urgently needed to co-create a heat action plan to improve community awareness and resilience.

Community-Based Trial Educational Heat Disorder Program in Local Salons for Older Adults

We investigated whether a combined program for heat disorder prevention can improve the behaviors and knowledge of heat disorder prevention in older adults participating in salons. This non-randomized parallel-group comparison study includes 59 participants from two salons. The intervention group met on alternate weeks on a salon day to watch an educational DVD and conduct hands-on education (Wet-Bulb Globe Temperature (WBGT) measurements inside and outside the meeting place). The intervention group conducted calls every other week except salon week to prevent action for heat disorder prevention information based on a leaflet and monitored WBGT in their bedrooms daily at bedtime. We assessed changes in recognition of heat disorders and prevention behavior between baseline, one and a half months after intervention, and post-season (approximately two months after baseline), using the Wilcoxon signed rank test. Recognition of heat disorder scores and preventive behavior improved from pre- to post-season in the intervention group. It was suggested that the approach toward older adults participating in salons could improve their recognition and behavior in preventing heat disorders.

High Temperatures and Cardiovascular-Related Morbidity: A Scoping Review

The primary objective of this review was to synthesize studies assessing the relationships between high temperatures and cardiovascular disease (CVD)-related hospital encounters (i.e., emergency department (ED) visits or hospitalizations) in urban Canada and other comparable populations, and to identify areas for future research. Ovid MEDLINE, EMBASE, CINAHL, Cochrane Database of Systematic Reviews, and Scopus were searched between 6 April and 11 April 2020, and on 21 March 2021, to identify articles examining the relationship between high temperatures and CVD-related hospital encounters. Studies involving patients with pre-existing CVD were also included. English language studies from North America and Europe were included. Twenty-two articles were included in the review. Studies reported an inconsistent association between high temperatures and ischemic heart disease (IHD), heart failure, dysrhythmia, and some cerebrovascular-related hospital encounters. There was consistent evidence that high temperatures may be associated with increased ED visits and hospitalizations related to total CVD, hyper/hypotension, acute myocardial infarction (AMI), and ischemic stroke. Age, sex, and gender appear to modify high temperature-CVD morbidity relationships. Two studies examined the influence of pre-existing CVD on the relationship between high temperatures and morbidity. Pre-existing heart failure, AMI, and total CVD did not appear to affect the relationship, while evidence was inconsistent for pre-existing hypertension. There is inconsistent evidence that high temperatures are associated with CVD-related hospital encounters. Continued research on this topic is needed, particularly in the Canadian context and with a focus on individuals with pre-existing CVD.

Heat exposure and cardiovascular health outcomes: a systematic review and meta-analysis

BACKGROUND

Heat exposure is an important but underappreciated risk factor contributing to cardiovascular disease. Warming temperatures might therefore pose substantial challenges to population health, especially in a rapidly aging population. To address a potential increase in the burden of cardiovascular disease, a better understanding of the effects of ambient heat on different types of cardiovascular disease and factors contributing to vulnerability is required, especially in the context of climate change. This study reviews the current epidemiological evidence linking heat exposures (both high temperatures and heatwaves) with cardiovascular disease outcomes, including mortality and morbidity.

METHODS

In this systematic review and meta-analysis, we searched PubMed, Embase, and Scopus for literature published between Jan 1, 1990, and March 10, 2022, and evaluated the quality of the evidence following the Navigation Guide Criteria. We included original research on independent study populations in which the exposure metric was high temperatures or heatwaves, and observational studies using ecological time series, case crossover, or case series study designs comparing risks over different exposures or time periods. Reviews, commentaries, grey literature, and studies that examined only seasonal effects without explicitly considering temperature were excluded. The risk estimates were derived from included articles and if insufficient data were available we contacted the authors to provide clarification. We did a random-effects meta-analysis to pool the relative risk (RR) of the association between high temperatures and heatwaves and cardiovascular disease outcomes. The study protocol was registered with PROSPERO (CRD42021232601).

FINDINGS

In total, 7360 results were returned from our search of which we included 282 articles in the systematic review, and of which 266 were eligible for the meta-analysis. There was substantial heterogeneity for both mortality (high temperatures: I²=93·6%, p<0·0001; heatwaves: I²=98·9%, p<0·0001) and morbidity (high temperatures: I²=98·8%, p<0·0001; heatwaves: I²=83·5%, p<0·0001). Despite the heterogeneity in environmental conditions and population dynamics among the reviewed studies, results showed that a 1°C increase in temperature was positively associated with cardiovascular disease-related mortality across all considered diagnoses. The overall risk of cardiovascular disease-related mortality increased by 2·1% (RR 1·021 [95%CI 1·020-1·023]), with the highest specific disease risk being for stroke and coronary heart disease. A 1°C temperature rise was also associated with a significant increase in morbidity due to arrhythmias and cardiac arrest and coronary heart disease. Our findings suggest heat exposure leads to elevated risk of morbidity and mortality for women, people 65 years and older, individuals living in tropical climates, and those in countries of lower-middle income. Heatwaves were also significantly associated with a 17% increase in risk of mortality (RR 1·117 [95% CI 1·093-1·141]), and increasing heatwave intensity with an increasing risk (RR 1·067 [95% CI 1·056-1·078] for low intensity, 1·088 [1·058-1·119] for middle intensity, and 1·189 [1·109-1·269] for high intensity settings).

INTERPRETATION

This review strengthens the evidence on the increase in cardiovascular disease risk due to ambient heat exposures in different climate zones. The widespread prevalence of exposure to hot temperatures, in conjunction with an increase in the proportion of older people in the population, might result in a rise in poor cardiovascular disease health outcomes associated with a warming climate. Evidence-based prevention measures are needed to attenuate peaks in cardiovascular events during hot spells, thereby lowering the worldwide total heat-related burden of cardiovascular disease-related morbidity and death.

FUNDING

Australian Research Council Discovery Program.

Knowledge Gaps and Research Priorities on the Health Effects of Heatwaves: A Systematic Review of Reviews

Although extreme weather events have played a constant role in human history, heatwaves (HWs) have become more frequent and intense in the past decades, causing concern especially in light of the increasing evidence on climate change. Despite the increasing number of reviews suggesting a relationship between heat and health, these reviews focus primarily on mortality, neglecting other important aspects. This systematic review of reviews gathered the available evidence from research syntheses conducted on HWs and health. Following the PRISMA guidelines, 2232 records were retrieved, and 283 reviews were ultimately included. Information was extracted from the papers and categorized by topics. Quantitative data were extracted from meta-analyses and, when not available, evidence was collected from systematic reviews. Overall, 187 reviews were non-systematic, while 96 were systematic, of which 27 performed a meta-analysis. The majority evaluated mortality, morbidity, or vulnerability, while the other topics were scarcely addressed. The following main knowledge gaps were identified: lack of a universally accepted definition of HW; scarce evidence on the HW-mental health relationship; no meta-analyses assessing the risk perception of HWs; scarcity of studies evaluating the efficacy of adaptation strategies and interventions. Future efforts should meet these priorities to provide high-quality evidence to stakeholders.

Hot weather as a risk factor for kidney disease outcomes: A systematic review and meta-analysis of epidemiological evidence

BACKGROUND

The occurrence or exacerbation of kidney disease has been documented as a growing problem associated with hot weather. The implementation of effective prevention measures requires a better understanding of the risk factors that increase susceptibility. To fill gaps in knowledge, this study reviews the current literature on the effects of heat on kidney-disease outcomes (ICD-10 N00-N39), including morbidity and mortality.

METHODS

Databases were systematically searched for relevant literature published between 1990 and 2020 and the quality of evidence evaluated. We performed random effects meta-analysis to calculate the pooled relative risks (RRs) of the association between high temperatures (and heatwaves) and kidney disease outcomes. We further evaluated vulnerability concerning contextual population characteristics.

RESULTS

Of 2739 studies identified, 91 were reviewed and 82 of these studies met the criteria for inclusion in a meta-analysis. Findings showed that with a 1 °C increase in temperature, the risk of kidney-related morbidity increased by 1% (RR 1.010; 95% CI: 1.009-1.011), with the greatest risk for urolithiasis. Heatwaves were also associated with increased morbidity with a trend observed with heatwave intensity. During low-intensity heatwaves, there was an increase of 5.9% in morbidity, while during high-intensity heatwaves there was a 7.7% increase. There were greater RRs for males, people aged ≤64 years, and those living in temperate climate zones. Similarly, for every 1 °C temperature increase, there was a 3% (RR 1.031; 95% CI: 1.018-1.045) increase in the risk of kidney-related mortality, which also increased during heatwaves.

CONCLUSIONS

High temperatures (and heatwaves) are associated with an elevated risk of kidney disease outcomes, particularly urolithiasis. Preventive measures that may minimize risks in vulnerable individuals during hot spells are discussed.

Mortality risk related to heatwaves in Finland - Factors affecting vulnerability

BACKGROUND

Heatwaves are known to increase mortality. However, there is a need for more quantitative information on factors affecting sensitivity to the adverse health effects, particularly in countries with cool summer temperatures.

OBJECTIVES

We evaluated mortality risk related to heatwave days in Finland. Risk was examined by age, sex, cause of death, and place of death, including health and social care facilities and homes. Mortality was also analysed for different patient subgroups in healthcare facilities.

METHODS

Heatwaves were defined as periods when the daily average temperature exceeded the 90th percentile of that from May to August in 2000-2014 for ≥4 days. In addition to all heatwave days, risk was analysed for short (4-5 days) and long (≥10 days) heatwaves. Mortality analyses were based on linking registry data on i) daily non-accidental and cause-specific mortality and ii) admissions to a health or social care facility. Statistical analyses were conducted using generalised estimating equations for longitudinal data analysis, assuming a Poisson distribution for the daily mortality count.

RESULTS

During all heatwave days, mortality increased among those aged 65-74 years (6.7%, 95% confidence interval 2.9-10.8%) and ≥75 years (12.8%, 95% CI 9.8-15.9%). Mortality increased in both sexes, but the risk was higher in women. Positive associations were observed for deaths due to respiratory diseases, renal diseases, mental and behavioural disorders, diseases of the nervous system, and cardiovascular diseases. Overall, effects were stronger for long than short heatwaves. During all heatwave days, mortality increased in healthcare facilities in outpatients (26.9%, 95% CI 17.3-37.2%) and inpatients. Among inpatients, the risk was higher in long-term inpatients (stay in ward > 30 days, 13.1%, 95% CI 8.6-17.7%) than others (5.8%, 95% CI 2.7-9.0%). At homes, mortality increased by 8.1% (95% CI 1.9-14.6%). Elevated risk estimates were also detected for social care facilities.

CONCLUSIONS

In Finland, a cold-climate Northern country, heatwaves increase mortality risk significantly among the elderly. Women are more susceptible than men, and many chronic diseases are important risk factors. To reduce heatwave-related deaths, preparedness should be improved particularly in hospital and healthcare centre wards, where the most vulnerable are long-term inpatients. However, measures are also needed to protect the elderly at home and in social care facilities, especially during prolonged hot periods.

The driving influences of human perception to extreme heat: A scoping review

Prior research demonstrates a link between heat risk perception and population response to a heat warning. Communicating a precise and understandable definition of "heat" or "heatwaves" can affect how a population perceives and responds to extreme heat. Still, little is known about how heat perception affects behavior changes to heat and heat communication across diverse populations. This scoping review aims to identify and describe the main themes and findings of recent heat perception research globally and map critical research gaps and priorities for future studies. Results revealed risk perception influences a person's exposure to and behavioral response to excessive heat. Risk perception varied geographically along the rural-urban continuum and was typically higher among vulnerable subgroups, including populations who were low-income, minority, and in poor health. A more integrated approach to refining risk communication strategies that result in a behavioral change and incorporates the individual, social, and cultural components of impactful group-based or community-wide interventions is needed. Research employing longitudinal or quasi-experimental designs and advanced statistical techniques are required to tease apart the independent and interacting factors that causally influence risk communication, heat perception, and adaptive behaviors. We advance a framework to conceptualize the structural, environmental, personal, and social drivers of population heat risk perception and how they interact to influence heat perception and adaptive behaviors. Our findings map future research priorities needed for heat perception and a framework to drive future research design.