Lack of guidelines for cold exposure among vulnerable outdoor workers

Abstract

Low temperatures pose a significant yet underrecognized occupational health risk, particularly for outdoor workers with climate-sensitive medical conditions such as diabetes, cardiovascular disease, and respiratory disorders. While cold exposure is often associated with Arctic and high-altitude regions, even temperate and warmer climates experience severe winter temperature drops, placing a broad spectrum of outdoor workers at risk. Despite extensive research highlighting the adverse health effects of cold stress and its contribution to global mortality rates, occupational health and safety (OHS) guidelines remain disproportionately focused on heat-related risks, neglecting the unique vulnerabilities of workers exposed to extreme cold. This paper critically examines the gaps in current OHS policies and regulations regarding cold exposure, emphasizing the urgent need for evidence-based guidelines that specifically address the needs of outdoor workers with preexisting health conditions. By integrating medical, environmental, and occupational safety perspectives, we propose a framework for comprehensive protective measures, including improved risk assessment protocols, workplace adaptations, and regulatory interventions. Addressing this oversight is essential not only for safeguarding workers’ health but also for promoting sustainable labor practices and enhancing resilience in industries where cold exposure is a persistent threat. Establishing clear, targeted guidelines will be a crucial step toward mitigating cold-related occupational hazards and fostering a healthier global workforce.

Background

Cold exposure remains an underestimated occupational hazard, despite its widespread impact on workers across various geographical and professional settings. Although cold exposure is relevant in both indoor (e.g. refrigerated facilities) and outdoor work environments, this paper focuses specifically on the risks faced by outdoor workers with climate-sensitive diseases. From high-latitude regions that endure prolonged winters to typically temperate or tropical areas that experience sudden drops in temperature, outdoor workers are increasingly vulnerable to the effects of cold weather [1]. Low temperatures are generally considered to be those below +10 – +15°C [2]. Consequently, about one-third of the world’s countries can be classified as having a cold climate based on the average annual temperatures [3]. These cold climates present significant challenges to occupational health and safety (OHS), making it essential to establish tailored guidelines to ensure safe and sustainable working conditions for outdoor workers (National Institute for Occupational Safety and Health (NIOSH) [4]. The need for robust OHS guidelines is further intensified by the accelerating impacts of climate change, which is worsening at an alarming rate and contributing to more extreme and unpredictable weather patterns globally [5].

There are concerns about a potential increase in extreme cold events; however, climate model projections are divergent. Some models suggest an increase, while others indicate a decline in both the frequency and intensity of extreme cold spells across most mid- and high-latitude regions. These patterns may also vary between areas with high and low climate variability [6–8]. According to Cohen et al, extreme cold spells in the Northern Hemisphere have become more frequent over the past four decades, with the severe cold periods in January and February 2021 which occurred across Europe, Asia, and the USA serving as stark reminders of the unpredictability of climate impacts [6]. This trend underscores the growing complexity of climate change, which is not only driving warmer temperatures but also amplifying extreme weather events, including intense cold fronts, heavy precipitation, and hazardous conditions such as icy surfaces and reduced visibility [9]. Outdoor workers thereby face escalating threats both to their physical and mental well-being, as these rapidly fluctuating conditions intensify OHS risks [5,10]. Despite the well-documented adverse effects of cold exposure and feeling cold, the focus on cold weather hazards in an occupational setting remains insufficient compared to heat-related risks, even though cold conditions affect a significantly larger portion of the global workforce [2,11,12]. This oversight is particularly surprising considering the prevalence of cold exposure and its mortality effects. For example, a Norwegian survey of living conditions revealed that while only 4% of workers are exposed to hot environments at work, a far larger proportion—17%—work in cold conditions [13,14]. Additionally, a global study spanning 13 countries (Australia, Brazil, Canada, China, Italy, Japan, South Korea, Spain, Sweden, Taiwan, Thailand, UK, and USA) between 1985 and 2012 found that mild cold temperatures are responsible for 7.2% of total temperature-related mortality, compared to just 0.4% attributed to heat. It should be noted that only 0.86% of mortality was related to extreme cold and hot temperatures [15]. A separate study analysed temperature-related mortality across 1,368 regions in Europe between 1991 and 2020. It recorded a median of 363,809 deaths related to cold and 43,729 deaths related to heat, resulting in a cold-to-heat death ratio of 8.3 to 1 [16].

Cold exposure triggers a range of physiological changes in the body, including altered circulation, shivering, and metabolic adjustments [17]. These bodily responses are influenced by factors such as the environment, clothing, physical activity, age, sex, fitness level, and pre-existing health conditions [18]. Workers with conditions such as diabetes, cardiovascular or respiratory diseases are possibly vulnerable to cold-related risks due to their impaired ability to regulate body temperature and maintain physiological homoeostasis [19–22]. This vulnerability is not only a personal health concern but also has significant implications for workplaces. Workplaces that fail to adapt to cold exposure risks may experience increased absenteeism, decreased productivity, and rising healthcare costs. Conversely, proactive measures can lead to a healthier, more engaged workforce, benefiting both employees and employers [23]. The concerning statistics regarding cold-related mortality and occupational injuries emphasise that cold exposure presents a significant, yet often underestimated, threat [15,24].

Although some International Organisation for Standardisation (ISO) standards concerning with ergonomics of thermal environments consider cold exposure at work [25], specific guidelines for outdoor workers with climate-sensitive conditions remain limited. Many workers regularly operate in cold environments, yet clear guidance for protecting those with conditions such as diabetes, cardiovascular disease, or respiratory illnesses is still lacking. This paper emphasises the need for comprehensive OHS guidelines for cold weather, with particular attention to outdoor workers whose health conditions may significantly affect their response to cold exposure.

Cold outdoor work environments and health problems

There are different definitions of cold work, where some define it as conditions that cause uncomfortable cooling sensations, while others define it as work in temperatures at or below +10 to +15°C [25,26]. Exposure to cold environments at work can involve cold air, immersion in cold water, or touching cold objects, impacting various parts of the body. Wind can further substantially aggravate cooling. In addition, the cold environment may be icy which can increase the risk of slip and fall accidents [23,27]. Cold outdoor work environments are common in numerous industries, including construction, agriculture, fishing and aquaculture, transportation, mining, and tourism [28]. Cold-related occupational injuries are not limited to extreme climates. Even in temperate regions, exposure to low or near-freezing temperatures can increase injury risk, by impairing performance and increasing slip hazards [29]. Some studies show overall effects may be small and not significant, but specific groups—such as workers in health and social services—can be more affected [30].

Exposure to cold can lead to various health effects, spanning musculoskeletal, respiratory, cardiovascular, and other bodily systems [2]. Musculoskeletal problems may include pain in neck, shoulder, lower back, and knee, as well as muscle swelling, cramps, restricted movement, muscle weakness, and paraesthesia [31]. Respiratory symptoms may manifest as an increased risk and severity of respiratory tract infections, asthma, and chronic obstructive pulmonary disease (COPD) [23,32]. Cardiovascular diseases may include angina pectoris, myocardial infarction, increased blood pressure, congestive heart failure, atrial fibrillation, and ventricular arrhythmias [33]. Other potential effects include skin complaints, peripheral nervous system disorders, and Raynaud’s phenomenon [34]. Both decreased physical and cognitive performance and altered work environment can predispose outdoor workers to an increased risk of accidents (e.g. slipping or falling) [35,36]. Furthermore, cold injuries such as hypothermia, frostbite, immersion foot, and chilblains are notable concerns [2,37]. Hypothermia occurs when the body loses heat faster than it can produce it and the core body temperature drops below 35.0°C, posing a serious risk to health [11]. Frostbite, or freezing cold injury, occurs when local tissue temperatures falls below the freezing point (approximately –0.5°C) [38]. In contrast, non-freezing cold injuries such as immersion foot arise from diminished blood circulation after prolonged cold exposure [39,40]. Another common issue, chilblains, manifests as inflammatory skin lesions triggered by cold, moist environments [41]. These conditions can significantly impact workers’ health and safety, highlighting the importance of preventive measures and proper protective clothing.

Climate-sensitive diseases and cold exposure

Certain groups of workers are more vulnerable to the adverse effects of cold environments, including older individuals and those with chronic conditions such as diabetes and cardiovascular, as well as respiratory diseases [42]. Diabetes is a global health problem, with approximately 537 million people affected worldwide in 2021, according to the International Diabetes Federation. This alarming number is projected to soar to 783 million by 2045 [43]. This high prevalence makes diabetes an important example when discussing the impact of cold exposure on workers, particularly since many individuals with diabetes are employed in environments with extreme temperatures [44]. For example, a study in Sweden found that construction workers—a group frequently exposed to cold conditions—have a higher prevalence of diabetes than the general population [44]. People with diabetes may have impaired peripheral nerve control and stiffer arteries, making it harder for their bodies to handle cold stress. These issues can limit circulation, raise blood pressure, and strain the heart, increasing the risk of cold-related complications [21,33,45,46]. They may also show impaired cardiovascular responses to temperature extremes, further compromising their adaptation to environmental stressors [21,47]. A study by Ikäheimo et al. in Finland also demonstrated a link between diabetes and an increased occurrence of cardiorespiratory symptoms in cold settings [20].

Another highly prevalent climate-sensitive disease is cardiovascular disease, including ischaemic heart disease and stroke, which are among the leading causes of death globally and major contributors to disability [48]. Research indicates that the incidence of cardiovascular illness and mortality rises during colder seasons or prolonged periods of unusually low temperatures (cold spells) [49,50]. Exposure to cold raises blood pressure and alters blood composition, potentially leading to conditions like hypertension, atherosclerosis, and myocardial infarction [19]. Cold exposure leads to higher cardiac preload and afterload, which in turn increases the myocardial oxygen demand. This added burden on the heart is further amplified when physical activity is performed in cold conditions. For individuals with pre-existing cardiovascular disease, working in cold environments can be especially challenging compared to those without these conditions [33]. A 2023 systematic analysis, including countries with both in extreme and moderate temperature, found that for every 1°C drop in temperature, cardiovascular-related mortality increased by 1.6% and morbidity by 1.2%. More strikingly, during short-term cold spells—periods of sustained extreme cold—cardiovascular mortality and morbidity rose sharply by 32.4% and 13.8%, respectively [19]. Similarly, a national study in Finland demonstrated that cold environments trigger cardiorespiratory symptoms in the general population—and that these symptoms are markedly more frequent in individuals with hypertension or cardiovascular disease [51].

Additionally, chronic respiratory diseases (CRD) are climate-sensitive and highly prevalent. CRD includes conditions like asthma, COPD, pneumoconioses, interstitial lung diseases, and pulmonary sarcoidosis, which are major global health concerns [52]. These conditions were responsible for 4.0 million deaths worldwide in 2019, making them the third leading cause of death. The global prevalence of CRD is estimated at 454.6 million cases, reflecting a significant health and economic burden [53]. Exposure to environmental factors, such as cold, dry air, can worsen these conditions by triggering physiological changes in the upper and lower respiratory tracts, leading to increased respiratory symptoms and pulmonary obstruction [22]. This is especially problematic for individuals with obstructive diseases like asthma and COPD, where such exposure can impair their ability to function effectively [23]. One study examining 60,000 deaths in Michigan, highlights the heightened risk of mortality among individuals with COPD during cold weather, underscoring the critical link between environmental factors and the exacerbation of CRD [54]. Countries with higher inter-annual variability in winter temperatures (which may not necessarily be very cold) tend to experience greater excess winter mortality compared to countries with consistently colder winters. Importantly, excess respiratory mortality can be demonstrated in plus degrees. For instance, a study conducted in Malta found that colder temperatures (ranging from 8–15°C) were strongly associated with increased respiratory mortality [55].

Occupational health guidelines for cold weather

Despite the increasing recognition of environmental risks in the workplace, a significant gap remains in OHS guidelines specifically addressing cold stress, particularly for individuals with climate-sensitive diseases. Various tools and models exist for assessing cold risk. These include health surveillance questionnaires, thermal comfort evaluation methods, and exposure duration calculators [25,56,57]. Additionally, ISO standards, such as ISO 11079:2007, provide methods for evaluating cold stress, determining necessary clothing insulation, and assessing local cooling effects [58]. However, these resources fall short in meeting the specific needs of the vulnerable group mentioned above. In light of this gap, the ISO 15743:2008 standard, titled Ergonomics of the Thermal Environment—Cold Workplaces—Risk Assessment and Management, was developed to assist employers and OHS in mitigating health risks for workers exposed to cold conditions [25]. Although the standard references certain climate-sensitive conditions, it does not provide tailored management strategies for individuals with these conditions. For instance, while it mentions cold-induced wheezing, it lacks specific recommendations for managing cold work in people with obstructive lung disease. This indicates a need for more comprehensive and actionable guidance. Furthermore, there is no available data on how widely the standard is used; inquiries about usage statistics revealed that such information is not collected. This limits the understanding of its implementation and visibility in practice.

Similarly, the Occupational Safety and Health Administration in the USA provides only a brief overview of cold stress, highlighting key risk factors and common cold-related issues such as hypothermia, frostbite, trench foot, and chilblains. However, it overlooks other critical health concerns, such as cardiovascular risks and metabolic complications, which are especially relevant to vulnerable worker populations, including those with diabetes [59]. Similarly, the European Agency for Safety and Health at Work published extensive guidelines on heat stress in 2023, recognising the growing risks posed by rising global temperatures. Yet, the agency has not released similar guidelines for cold stress, leaving a significant gap in occupational health and safety resources [60]. The International Labour Organisation (ILO) has focused primarily on heat-related risks and there are no equivalent data or resources on occupational cold exposure available on their website [61,62]. Surprisingly, the World Health Organisation, despite its broad scope on global health issues, offers no substantial guidance on occupational cold risks, highlighting the ongoing neglect of this area within the international health and safety discourse. This lack of attention to cold stress underscores the urgent need for comprehensive guidelines and a more robust global response to the occupational risks associated with cold environments.

Recommendations

Currently, there are no OSH guidelines specifically addressing the risks of cold exposure for outdoor workers with climate-sensitive diseases. To help fill this gap, firstly, it would be valuable to prioritise targeted research to better understand how factors such as age, specific health conditions, and exposure duration influence vulnerability, providing a foundation for informed guidance. Attention could also be given to enhancing workplace protections, including the adequacy of protective clothing, respiratory equipment, work organisation, and regular health monitoring for those at greater risk. Existing research provides evidence-based recommendations for managing these risks, which can inform the development of practical guidelines. For example, Stjernbrandt et al. suggest that for individuals with type 2 diabetes, those managing the condition with oral medication should monitor metabolic control more frequently, while insulin-dependent individuals should avoid working alone in cold conditions. Patients with cardiovascular disease require more frequent blood pressure monitoring, and those with manifest ischaemic heart disease should undertake less physically demanding tasks, minimise cold exposure, wear highly insulated clothing, and undergo medication reviews. Stroke patients, particularly those with impaired temperature regulation, should avoid repeated exposure to cold environments. For individuals with obstructive pulmonary disease, they recommend modifications such as engaging in less physically strenuous tasks, reducing exposure time in cold conditions, and using specialised protective equipment, including heat exchanger masks or heated supplied-air respirators [63]. Despite these recommendations for managing health risks while working in the cold, significant gaps remain, and further research is needed to develop comprehensive, evidence-based guidelines that effectively protect outdoor workers with climate-sensitive diseases in cold conditions.

Secondly, guidelines that are adaptable to local climate conditions may be particularly helpful, as workers in milder climates are often less prepared for cold exposure. Engaging stakeholders—including policymakers, healthcare professionals, employers, and workers themselves—can help ensure that any guidance is practical, relevant, and feasible. Finally, aligning these efforts with broader initiatives, such as the United Nation’s Sustainable Development Goals (SDGs), may further support worker health, safety, and resilience to climate-related risks. These guidelines directly contribute to SDG 3 (Good Health and Well-being), SDG 8 (Decent Work and Economic Growth), and SDG 13 (Climate Action), all of which emphasise resilience and adaptive capacity to climate-related risks, critical for protecting vulnerable workers in cold environments [64].

However, we should notice that this paper is an opinion piece, and as such, it may not encompass all existing literature on occupational cold exposure. While the paper highlights vulnerable groups such as workers with diabetes, cardiovascular, or respiratory diseases, other potentially susceptible populations—such as older workers without diagnosed conditions—are less addressed. Recommendations are based on a combination of observational studies, standards, and expert opinion, with limited empirical data specifically evaluating the effectiveness of interventions in outdoor workers. Furthermore, uncertainties in climate projections and the variable adoption of existing guidelines underscore the need for further research to validate and operationalise these recommendations.

Conclusion

In conclusion, the development of comprehensive occupational health and safety guidelines for cold weather for outdoor workers with climate-sensitive conditions is essential to safeguard their well-being and safety. By doing so, we can promote a safer, healthier, and more resilient workforce. This effort not only helps reduce the health risks associated with cold exposure but also supports the economic stability and sustainability of industries operating in cold climates. Overall, developing such guidelines represents an important step toward creating inclusive, evidence-based, and adaptive workplace practices that protect vulnerable workers while fostering long-term occupational and economic resilience.

Funding Statement

Mojdeh Rafieian is supported by the Arctic 6 Fellowship Programme.

Disclosure statement

On behalf of all authors, the corresponding author states that there is no conflict of interest.

Ethics approval

This is an opinion paper. So, no ethical approval is required.