Introduction
Working in cold environments can expose workers to cold stress, which can cause fatigue, reduced dexterity and mobility, increased risk of injury and serious health problems such as hypothermia and frostbite. Prolonged exposure to cold can also increase the likelihood of developing musculoskeletal disorders (MSDs). Particularly at risk are outdoor workers in cold, windy or wet conditions, workers in artificially cold environments such as refrigerated warehouses or cold storage facilities and workers in poorly heated workplaces during the cold season. Personal factors such as age, gender, health conditions (e.g. hypertension, hypothyroidism and diabetes) and certain medications can also affect the health effects of working in cold environments.
Effectively managing the hazards of working in cold environments requires a structured and proactive approach. Cold-related risks should be fully integrated into the organisation's overall occupational safety and health (OSH) strategy, based on thorough risk assessments and supported by clear policies, planning and preventive measures.
What is a cold working environment?
Definition
A cold environment is any environment in which environmental conditions can result in significant heat loss from the human body. These environments can cause sensations of cold, physical discomfort and, if prolonged or uncontrolled, decreased body temperature[1] [2][3]. In occupational settings, such environments may lead to increased risks. Even at ambient temperatures that are just below 20 °C, there may be problems in terms of performance and health[4] [5]. At lower temperatures (i.e. below +10 °C and especially below +5 °C, there is an increased risk of thermal stress or cold-related health effects[6] [5], especially when combined with wind and moisture. Such cold working conditions are common and can be found in different sectors, both indoors (e.g. cold storage, food processing, or refrigerated warehouses) and outdoors (e.g. construction, agriculture, transportation).
Thermoregulation and factors influencing thermal balance
Thermoregulation is the physiological ability of the human body to maintain a stable core temperature despite changes in external environmental conditions. For physical and chemical processes to function optimally, the human body requires a constant, high temperature[5]. The core temperature of the human body is normally 37 °C ±1-2 °C[7]. Body temperatures below this range are referred to as hypothermia and above as hyperthermia. A person is in thermal balance when heat production equals heat loss.
The human body produces heat using its muscles and its organs[8] [9]. Heat is transferred from the body to the environment by radiation (heat radiating from the body surface to colder surfaces in the environment), convection (movement of air or water), conduction (direct contact with a cold object or liquid), evaporation (sweat transferred as vapour to the environment) and respiration[7][9][5]. When heat loss exceeds heat production, core body temperature drops, increasing the risk of hypothermia and reduced physical and cognitive performance.
Environmental factors (air temperature, wind and humidity) and behavioural factors (physical activity and clothing) affect thermoregulation[6].
- Air temperature: the lower the ambient temperature, the greater the heat loss by conduction, convection and radiation.
- Wind speed: wind accelerates convective heat loss and increases the wind chill effect, making temperatures feel colder than they are.
- Humidity and moisture: wet clothing or high humidity increases heat loss and reduces insulation, especially if sweat cannot evaporate. However, at temperatures below about -5 °C, the moisture content of the air is so low that it can generally be regarded as dry[5].
- Physical activity: higher levels of activity generate metabolic heat, but also increase sweat production, which can later cool the skin if it evaporates slowly.
- Clothing: the type, layering and moisture management properties of clothing determine its thermal insulation. Clothing that is too light or gets wet can accelerate cooling.
Individual factors also affect human thermal balance and subsequent physiological responses. Some groups of workers have an impaired ability to maintain thermal balance in the cold. These include older workers[10], those with low body fat, underlying cardiovascular or neurological conditions, or those taking certain medications (i.e. medication affecting fluid balance, vasoconstriction and/or dilation, and cardiac function)[11]. Women are also more susceptible to heat loss and less tolerant of cold putting them at greater risk of cold-related injuries and illnesses[10] [12]. Fatigue, dehydration and poor nutrition also impair the body's ability to thermoregulate and produce heat, thereby increasing the risk of health problems in cold environments.
Effects of working in the cold
Working in cold environments places considerable strain on the human body and results in cold stress, which can lead to fatigue, reduced performance and a range of health outcomes such as hypothermia, frostbite, trench foot, chilblains and musculoskeletal disorders (MSDs). Cold exposure also reduces physical, especially manual, and cognitive performance[13] [14], increasing the likelihood of errors and accidents.
Physiological responses to cold
In cold environments, the body activates thermoregulatory mechanisms to minimise heat loss and increase heat production[1]. In addition, cold discomfort triggers behavioural responses that support these physiological defences and may include adding or adjusting layers of clothing, seeking shelter, or using external heat sources to maintain comfort and safety[8] [15] [16].
One of the body’s initial physiological reactions is vasoconstriction, the narrowing of blood vessels by small muscles in their walls, especially in the feet and hands. This reduces blood flow to the skin and extremities, thereby limiting the transfer of heat from the core to the body’s surface[8][10][15]. While protective, this process accelerates tissue cooling in the hands, fingers, feet and face, impairing sensory functions and dexterity. Cooling of the tissues in the hands and fingers can rapidly reduce the tactile sensation of the skin and impair neuromuscular function, affecting the dexterity of the fingers[12]. Dexterity is defined as a motor skill determined by a range of arm, hand and finger movements and the ability of the hands and fingers to perform manipulations[17]. In general, dexterity is reduced when the skin temperature of the hand falls below 22 °C and becomes critical below 15 °C[18]. The ISO 11079 standard suggests that finger temperatures should be higher than 24 °C to maintain good hand function[19].
Another key physiological response is shivering, which generates heat through involuntary muscle contractions[8] but also contributing to fatigue and reducing a person’s ability to concentrate on tasks. The intensity and extent of shivering varies according to the severity of the cold stress experienced[16]. Although shivering protects against the cold, it compromises cardiovascular and neuro-muscular functions[3] and can impair work performance by affecting cognition and decreasing manual dexterity and motor coordination[20].
Exposure to the cold affects respiratory function because cold, dry air irritates and cools the upper and lower airways. Cardiovascular reactions include an increase in blood pressure and heart rate, which are caused by vasoconstriction, among other things. Blood viscosity also rises, which increases the heart's workload. Neuromuscular function slows as tissues cool, which impairs muscle contraction, coordination, and nerve conduction[16].
Together, these physiological responses can lead to a decline in performance, cold injuries and other cold-related health problems.
Effects on physical and cognitive performance
Cold exposure affects physical performance by reducing manual dexterity, muscle and grip strength, speed, tactile sensitivity, muscle coordination and fine motor control as well as by causing pain and distracting attention. This can have a significant impact on a worker's ability to use tools, operate machinery or perform precision tasks[21][7][22][23]. In addition, the use of protective gloves and clothing can further reduce physical performance due to their weight and bulkiness, as well as interfering with sensory functions and dexterity[7][3].
Tasks requiring precise and controlled finger movements (e.g. tying knots, tightening screws) are more likely to be affected by cold exposure than those involving hand, arm and shoulder movements (e.g. hammering, pulling wire or rope)[12]. Manual performance is affected not only by cold temperatures, but also by contact with cold surfaces and the wearing of gloves[24].
Two main theories have been proposed to explain how exposure to cold affects cognitive performance[11]. The first, known as the arousal hypothesis, suggests that a slight decrease in body or environmental temperature can increase alertness and focus. According to this view, moderate exposure to cold can stimulate the nervous system, leading to increased alertness and improved task performance, for example, a driver might feel more alert in a cool car[25][3][26].
In contrast, the distraction hypothesis suggests that cold acts as a stressor, diverting cognitive resources away from the task at hand and towards managing physical discomfort and thermoregulation. This effect is particularly pronounced with prolonged or more intense exposure to cold, where shivering, numbness and discomfort distract attention and reduce cognitive efficiency[25][3][26].
Overall, while mild cold may temporarily increase alertness, the majority of research supports the distraction theory for colder or longer exposures. Most evidence suggests that cognitive performance declines with increasing exposure to the cold, through effects such as slower reaction time, impaired working memory and reduced accuracy in decision making[11] [25].
Impact on safety: increased risk of accidents and injuries
The combination of impaired physical and cognitive performance and environmental hazards leads to an increased risk of occupational accidents and injuries in cold conditions, particularly in outdoor environments. A study analysing temperature and occupational injury data in Spain from 1988 to 2019 found that cold exposure was associated with a 4% higher risk of work-related injuries[27]. Similarly, an Italian study[28] examining over 2.2 million occupational injuries between 2006 and 2010 found that both heat and cold exposure increased the risk of injury. The research also highlighted that women and older workers were particularly vulnerable to injuries related to low-temperature exposure[28]. An Australian study[29] found that 1.66% and 0.66% of work-related injuries and illnesses were due to heat and cold, respectively. In terms of associated costs, the figures were 1.53% and 1.33% respectively, suggesting that cold-related injuries and illnesses tend to be more severe and result in longer periods of absence from work[29].
Research confirms that cold working conditions, especially in outdoor settings, are linked to increased accident rates due to the combined effects of impaired physical and cognitive performance, as well as environmental hazards such as[30]:
- Slippery surfaces (ice, snow)
- Reduced visibility (fogging or blowing snow)
- Decreased dexterity, muscle strength, coordination and reaction time
These conditions can lead to a range of incidents, including:
Cold injuries
Cold injuries occur if the body cools down severely enough[4]. Cold injury is a term that can be used to describe both injuries that have a central effect such as hypothermia and ones that primarily affect the peripheries. Peripheral cold injuries can be subdivided into freezing cold injuries and non-freezing cold injuries[31] [32][12].
Freezing cold injuries such as frostbite involve the actual freezing of tissues and usually affect exposed or poorly insulated peripheral areas like fingers, toes, nose, ears. They can lead to long-term complications like necrosis, infection, and permanent tissue loss.
Non-freezing injuries also cause tissue damage but without actual freezing. This type of injury is caused by prolonged exposure to cold conditions, usually between 0 °C and 10 °C often in combination with humid environment, immobility and constrictive clothing or footwear[33]. People with Raynaud's phenomenon are more likely to suffer from peripheral cold injuries due to their impaired thermoregulation and delayed rewarming caused by the constriction of blood vessels in the digits of the hands and feet[34].
Hypothermia is a systemic cold Injury characterised by a whole-body drop in core temperature, typically below 35 °C. It affects the entire body and can range from mild (shivering, confusion) to severe (loss of consciousness, cardiac arrest). Hypothermia is often caused by immersion in cold water, or by wet clothing after immersion but can also occur in cold air[35] [36].
Other cold-related health effects
Exposure to cold can lead to a wide range of symptoms and illnesses affecting the skin, respiratory system, cardiovascular system, peripheral circulation, and musculoskeletal system
Respiratory effects
Breathing cold, dry air triggers significant changes in the upper and lower respiratory tract, leading to discomfort and irritation[4]. In a controlled study with 34 participants exposed to cold air (0 °C to -17 °C), over 50 different symptoms were reported[37]. Respiratory symptoms were most common (e.g. runny nose, irritation of the mouth and throat) affecting both healthy individuals and those with pre-existing conditions like allergic rhinoconjunctivitis or obstructive lung disease[37]. Prolonged occupational exposure to cold may lead to more persistent respiratory effects. A survey-based cohort study between 2015 and 2021 in a sample of 5017 Swedish individuals found that occupational cold exposure was associated with incident wheeze and productive cough in previously healthy workers[38]. The results of this study are consistent with other studies reporting an association between occupational cold exposure and respiratory symptoms such as shortness of breath, wheezing and chronic cough[39]. These symptoms often serve as early warning signs of potential long-term health consequences.
Cold environments may also worsen respiratory symptoms, especially in people having a chronic respiratory disease (e.g. asthma, chronic obstructive pulmonary disease) or who are smokers[11].
Effects on the skin
Cold exposure can directly affect the skin and sensory perception. As the skin temperature drops, the first sensation the skin experiences is thermal discomfort, followed by a sensation of cold, and then cold pain and injury[33]. Skin problems and complaints include cold sensations (especially on the face and extremities), dryness, pain, itching, irritation, redness and swelling[40][15]. Abnormal skin responses to cold are usually the result of prolonged exposure to moderate cold (0 to +15 °C). Studies of working conditions in artificial cold[41][7], have shown that workers often experience cold discomfort in the hands and fingers (skin temperatures below 25 °C), with some workers even approaching the pain threshold (around 10 °C)[41].
Chronic skin disease alters the characteristics of the skin, which can increase its sensitivity to cold, causing discomfort, pain, reduced performance and even injury4. In some cases, workers may develop chronic skin conditions such as cold urticaria. Cold urticaria is a group of hypersensitivity reactions to cold in which skin swelling, wheals and hives occur after the skin has rewarmed after or during exposure to cold[33].
Cardiovascular effects
Prolonged cold exposure can also impact the cardiovascular system and peripheral circulation. Raynaud's phenomenon is a common clinical disorder characterised by recurrent vasospasms of the fingers and toes, often associated with exposure to cold temperatures and hand-arm vibration[4]. Therefore, workers who handle hand-held vibrating machines, such as grinders, hammers or drills, in cold conditions are at an increased risk of developing Raynaud's phenomenon[42]. If the condition is not recognised in its early stages, it can permanently affect blood circulation in the fingers or toes[43].
Cold causes blood vessels to constrict, creating more pressure in the circulatory system, leading to an increase in blood pressure and forcing the heart to work harder. It can also increase the viscosity of the blood, increasing the risk of blood clots, stroke or heart attack[44]. The combination of cold and hard work adds to the stress on the cardiovascular system[4]. These risks are greater for people with existing cardiovascular disease. A systematic review and meta-analysis of cold exposure and cardiovascular disease outcomes demonstrated that cold exposure contributes to increased cardiovascular morbidity and mortality[45].
Musculoskeletal disorders
Musculoskeletal problems are also common. Cold environments can cause muscle stiffness, joint discomfort, and increased risk of musculoskeletal pain, particularly in workers performing repetitive tasks. Reduced blood flow to muscles and ligaments can lead to pain in the shoulders, back, and hands. Several studies have demonstrated that working in a cold environment is associated with an increased prevalence of musculoskeletal disorders such as back[46] [47] [48] [49], neck[46] [47] [48] [49], shoulder[46][48], hand and arm pain[50] as well as lumbar radiculopathy[47] [48]. Working in cold conditions for more than a quarter of the time was also found to increase the risk of future musculoskeletal disorders[51].
Jobs at risk
Extreme cold is present in many sectors of activity, both outdoors in winter and indoors in all seasons[15][5][9].
Indoor cold exposure occurs mainly in the food and drink industry, where work is carried out in temperature-controlled warehouses. Indoor cold work areas can also be found in other industries such as the pharmaceutical industry (medicine storage), flower wholesale and horticulture (flower storage) and the chemical industry. The main temperature ranges are +1 to +5 °C for chilled rooms and -20 °C to -30 °C for frozen products, although these can vary depending on the requirements of the product[52]. The thermal environment for these activities is constant and predictable, making cold risk management easier. However, cold indoor work environments tend to involve prolonged exposure to cold temperatures and frequent movement from cold to warm environments, and therefore pose a higher risk to workers[15][5][9][4]. Working in artificial indoor environments, particularly those with controlled sub-zero temperatures, poses significant health risks to workers. Field studies have documented the harsh conditions in artificial cold stores, where air and mean radiant temperatures can reach -20 °C or below (see box 1).
In addition to cold temperatures, workers in chilled and cold storage rooms are often exposed to other indoor environmental factors such as humidity, air movement, draughts, noise, cold work surfaces, contact with cold or frozen products and the use of cold tools[53]. Furthermore, the work is often repetitive, increasing the risk of MSDs.
Another major concern with artificial cold storage is the exposure of the respiratory system to extremely cold, dry air, which can cause respiratory discomfort, airway irritation and long-term respiratory problems[54].
Box 1: Selected findings from studies carried out in artificial indoor environments A study by Groos et al.[55] compared order picking tasks within a group of 60 workers in a chill room (+3 °C) and in a cold store (−24 °C). Their analyses showed that, overall, picking at -24°C was perceived by workers as more physically demanding than picking at +3 °C for the same workload. Raimundo et al.[54] carried out field measurements in 101 different indoor workplaces from 6 sectors of activity (fish, meat, dairy food production, food preservation, food distribution and pharmaceutical distribution). The study results show that when working in cold conditions, clothing insulation is often inadequate, and exposure times are longer than recommended. This combination leads to higher than acceptable levels of whole-body cooling, putting workers at risk of cold-related health problems[56][54]. The study also found that skin temperatures in the fingers and hands are significantly lower than those in the core of the body[54]. In a study of 24 workers in cold storage facilities (with temperatures ranging from -43 °C to -62 °C) at a freeze-drying coffee company[57] 50% reported episodic finger symptoms, such as white fingers, indicating vasospasm (Raynaud’s phenomenon) and 20% experienced other peripheral circulatory symptoms, such as numbness or tingling in the extremities. A study of workers (n=207) in frozen food plants found that the combination of repetitive work and cold led to an increased incidence of carpal tunnel syndrome (9.4 times the risk) compared with repetitive work without exposure to cold (2.2 times the risk)[58].
|
Outdoor cold exposure is common in sectors such as construction (see box 2), agriculture, forestry, fishing, mining and quarrying, waste collection, utility installation and maintenance, offshore installations, military operations, maritime rescue and green jobs. It is particularly relevant in high latitude areas where winter lasts for many months i.e. Scandinavia. Climate change has generally led to a decline in the frequency and intensity of cold extremes. However, due to Arctic warming and changes in the Arctic atmospheric circulation are increasing the variability and the risk of extreme cold events[59]. Studies[60][61] show that northern and north-western Europe could still experience intense, but episodic, cold spells. By contrast, warming trends are increasingly dominant in central and southern Europe, where cold events have become rarer and shorter in duration[62].
Outdoor exposure to cold is less predictable. Environmental conditions, including variations and unexpected changes in temperature, wind speed and precipitation, increase the risks[15][5][9].
Box 2: Construction work Data from Finland show that the construction sector has the most hours with cold exposure per week, more than, for example, in agriculture or among military personnel[21]. Studies show that construction workers face many health challenges in winter due to cold temperatures and extreme weather conditions[63]. Their tasks, physical workload, work environments, and weather conditions are constantly changing. Wind, rain, snow and icy surfaces are additional environmental risk factors associated with cold[13] . A study in a Finnish construction company found that 73% of the workers (n = 46) had experienced cold discomfort, cold-related symptoms or cold injuries, mainly respiratory symptoms and symptoms in the extremities. According to the respondents, this resulted in reduced work performance (52%) and reduced motivation to work (78%). The most problematic environmental factors were wind, cold tools and wet conditions. An increased risk of accidents at work due to cold conditions was perceived by 76% of respondents. The hands and feet were most susceptible to the negative effects of cold[7]. |
Risk assessment
Effective risk assessment in cold working environments is essential to protect worker health and safety It is also the cornerstone of OSH management, as required by the OSH Framework Directive (89/391/EEC)[64].
Based on the principles proposed in ISO 15265[65] and further detailed in ISO 15743[66], the assessment of the risks of working in cold conditions can be divided into three steps. This approach combines straightforward observation techniques for identifying and addressing basic issues (step 1) with advanced measurements and specialised methods for resolving more complex problems (steps 2 and 3)[19].
Figure: risk assessment steps
Source[21]
Step 1: Observation
The first step involves directly observing the working conditions while actively involving workers in the process. Involving workers is essential because it allows their first-hand knowledge and experience to be integrated. Moreover, changes that are initiated by or developed with worker input are generally more readily accepted and implemented[19]. To facilitate this step, an observation checklist can be used. ISO 15743 offers a user-friendly checklist based on eight key checkpoints, including topics such as exposure to cold air, contact with cold materials or the use of PPE. These checkpoints help to quickly identify obvious risks and initiate immediate improvements.
Step 2: Analysis
In the second step, a detailed analysis focuses on the issues identified during the observation stage. This may involve more in-depth and quantitative assessments using standardised methods[19]. Examples are:
- ISO 11079 (IREQ Calculation)[67]: this standard provides a method for calculating the Insulation Required (IREQ) for clothing[68], which is based on environmental conditions (air temperature, wind speed, humidity), the metabolic rate of the work performed (work intensity) and thermal properties of clothing. The calculated IREQ value can be considered as a cold stress index: the higher the value, the greater the risk of body heat imbalance. The IREQ indicates the level of protection that should be provided by the clothing and can be compared with the actual insulation of the clothing worn by the worker to indicate whether it is adequate for the conditions. If the actual level of protection is less than the calculated IREQ, exposure to cold should be limited in time to prevent progressive cooling of the body. Therefore, ISO 11079 includes methods to determine the (duration limited exposure, DLE), which is the maximum recommended exposure time with the available intrinsic clothing[69][54]. Online tools are available to simplify these calculations[70].
- ISO 13732-3[71] assesses the risk of cold injuries when workers touch cold surfaces with bare skin. The assessment considers factors such as surface material properties, surface temperature, ambient temperature, duration of contact, and the characteristics of the skin[19].
- Windchill Index: the wind chill temperature is a temperature that describes the cooling effect on the skin. The index can be read from tables in EN 11079 or calculated based on the wind speed and the air temperature[72]. The index accounts for the combined effect of air temperature and wind speed, providing a measure of how cold it actually feels and is better suited for outdoor scenarios[73] [54].
Depending on the situation, other complementary methods may be needed to gain a full understanding of the risks.
Step 3: Expertise
The final step is an expert evaluation, in which professionals such as occupational hygienists and occupational health specialists analyse the results of the previous phase to quantify and estimate the risks posed by the cold. This expert evaluation ensures that the risk assessment approach is not only compliant with standards but also adapted to the specific circumstances of the workplace.
Workplace strategies for reducing risks of cold stress
Cold risk management should be fully integrated into the company's OSH management system and practices to ensure the implementation and follow-up of preventive measures[13] .
Employers should adopt a structured approach to cold risk management in line with the OSH Framework Directive[64]. As mentioned above, this approach starts with a comprehensive risk assessment to identify and evaluate cold-related hazards. It also includes the development of clear policies and preventive measures to manage these risks. Employers must also involve workers and their representatives in identifying risks and developing appropriate preventive measures. In addition, the provision of instructions, safe working practices, information and training ensures that workers understand the risks and the steps they can take to protect themselves and their colleagues[74].
The Online interactive Risk Assessment (OiRA) tool Heat & Cold[74] helps organisations manage thermal risks. The tool includes general modules (policy & planning, thermal comfort) as well as specific modules on working in cold conditions, both indoors and outdoors.
Prevention measures for working in the cold
The prevention of cold-related risks in the workplace requires the implementation of appropriate measures based on the results of the risk assessment. Prevention measures higher in the hierarchy of control should be prioritised, focusing first on the most effective measures by eliminating the risk, i.e. avoiding working in the cold, e.g. by adapting work processes or automating tasks. Prevention measures must be tailored to the situation and range from workplace design and technical solutions to organisational strategies. The table below gives an overview of prevention measures for working in cold environments.
Table: Workplace design, technical and organisational measures
| Type of measure | Indoor | Outdoor |
| Automation | - Automate tasks in cold environments e.g. use robotics or automated systems such as automated guided vehicles or automated pallet conveyors
| - Avoid working in the cold, e.g. use of automated work processes, remote-controlled vehicles or machinery
|
| Workplace design | - Separate cold areas from other work areas (e.g. strip curtains, high speed doors or air curtains)
- Provide appropriate flooring
- Control humidity (proper ventilation, dehumidification systems)
- Reduce draughts (control air velocity)
| - Install barriers, shelters or tents to shield work areas from wind and other adverse weather conditions
- Keep work areas clear from water, ice and snow
|
| Equipment | - Assess cold-related issues when selecting equipment (include OSH in purchasing procedures)
- Provide easy to use tools considering the reduced dexterity and the use of (thick) gloves
- Provide hand tools with insulated handles
- Provide vehicles with enclosed heated cabins to protect operators from cold temperatures
- Ensure equipment is easy to maintain to reduce exposure time in cold environments for maintenance workers
- Store tools, equipment and machinery in a heated space
|
| Planning work tasks | - If possible, move the work tasks to warmer areas
- Adapt work tasks to avoid static standing or sitting, alternate between sitting/standing/moving
- Rotate workers between different tasks and warmer parts of the building.
| - Take into account environmental conditions when planning tasks (avoid working during periods of cold and/or adverse weather)
- Schedule outdoor tasks during the warmest part of the day
- Rotate workers between outdoor and indoor tasks in warm environments
- Conduct morning briefings to discuss weather conditions
- Provide the possibility to stop work and take shelter in case of rapidly deteriorating weather conditions
|
| Self-pacing | - Provide workers the ability to self-pace their work tasks.
- Implement flexible work arrangements providing workers the ability to self-pace their work tasks and/or take more frequent short breaks.
|
| Work-rest cycles | - Implement appropriate work-rest cycles that alternate work in cold areas with recovery periods in warmer spaces
- Consider the environmental conditions, work intensity, individual needs and vulnerabilities
- Provide heated break areas with appropriate facilities, i.e. for drying wet or damp gloves and clothing, and taking warm drinks
|
| Monitoring and supervision | - Introduce a buddy system, avoid lone working in cold environments
- Organise training for workers in the buddy system on how to recognise the signs of cold stress and what to do in the event of an emergency
- Use wearable technology to detect signs of cold stress
|
| Management of PPE | - Ensure sufficient stock of appropriate PPE (see also below)
- Ensure that spare sets of dry clothing are readily available in case PPE is wet.
- Provide access to extra layers of clothing for warmth
- Clean, maintain and store PPE in accordance with the manufacturer's instructions.
|
| Health surveillance | Organise health surveillance for workers at risk of cold stress Take into account vulnerable groups, i.e. pregnant and breastfeeding workers, older workers, workers with pre-existing health conditions or who use certain prescribed medications
|
| Emergency planning | - Include specific emergency procedures on cold stress in the overall emergency plan
- Provide appropriate first-aid arrangements such as first-aid kits with thermal blankets
- Train workers on how to respond to cold-related emergencies
- Organise emergency drills on a regular basis
|
| Training and information of workers | - Organise training for workers. Topics may include the risks of cold stress, prevention measures, use of PPE, how to recognise early signs of cold stress, personal factors that may put people at greater risk, etc.
|
Source: based on[75][74][21]
Personal Protective Equipment (PPE) for working in the cold
PPE should only be used after all other reasonably practicable control measures have been taken to eliminate or minimise the risk. When selecting and implementing personal protective equipment, employers must consider the obligations set out in Directive 89/656/EEC on the use by workers of PPE at the workplace[76]. PPE should be carefully selected, taking into consideration the type of activity, ambient conditions, length of exposure, user preferences and the level of performance required, so that it provides appropriate protection without compromising comfort or mobility.
Protective clothing
Cold protective clothing creates a microclimate around the worker, preventing harmful cooling and allowing the worker to maintain thermal balance[9]. The clothing should be well insulated, lightweight, multi-layered, well-fitted and moisture-wicking.
The requirements for cold protective properties of clothing are described in two standards, EN 14058 for clothing in cool environments (> -5 °C)[77] and standard EN 342 for clothing in cold environments (< -5 °C)[78].
Standard EN 14058 classifies garments according to their thermal resistance, with four classes. Class 4 provides the highest level of thermal insulation. Other performance levels include air permeability (resistance to wind penetration, 3 classes) and an optional test for water penetration resistance.
Standard EN 342 expresses the thermal insulation in Icler. The higher the Icler value, the better the insulation against cold. In addition, there are three classes of air permeability, with class 3 providing the highest level of protection. In windy conditions, class 3 garments will provide the best protection, but in less windy conditions, class 1 garments offer more comfort because they are more breathable. EN 342 also includes an optional test for protection against water penetration.
Depending on the working conditions, protective clothing should offer additional protective properties such as good visibility (EN ISO 20471[79]) and protection against adverse weather conditions like wind and rain (EN 343[80]). These protective properties are particularly important when working outdoors.
Some practical guidelines for the use of cold-protective clothing include[12] [21]:
- ease of use: clothing should be easy to put on and take off. Clothing should allow for easy operation, even with cold or gloved fingers. Buttons should be avoided. Zippers and other fasteners must function effectively in snowy or windy conditions.
- layers: clothing should be worn in layers, and the layers should not be tight to one another. This allows for better temperature control by adding or removing layers as needed, depending on activity level and environmental conditions. The design of the outer layer should allow easy adjustment of openings (e.g. at the neck, sleeves, and wrists) for temperature regulation.
- moisture: inner layers should be moisture-wicking to keep the skin dry, reducing the risk of cold stress. Ensure clothing stays dry, and replace it if it becomes wet from snow, rain, or sweat, as moisture reduces the insulation value.
- appropriate overlap: garments should provide sufficient overlap i.e. between vest and pants, between sleeves and gloves.
- freedom of movement: the design should accommodate bent postures without compressing layers or reducing insulation effectiveness.
Protective gloves
Hands are vulnerable to local cooling. Protective gloves should have an appropriate level of thermal insulation, be made of flexible materials that will not be damaged by low temperatures and be well fitted to allow flexibility in gripping and handling items[17]. However, regardless of the ambient temperature, gloves are detrimental to dexterity. The sense of touch is affected by glove use and tactile performance also decreases, especially if the glove does not fit properly. Even thin gloves can reduce finger dexterity by 60% compared to bare hand performance in cold conditions[81]. Factors affecting finger and manual dexterity are related to the glove material, such as its thickness, elasticity, deformability, as well as to the shape of the glove itself[24].
Cold temperatures, especially below freezing, can cause accelerated degradation of the glove material, making it stiffer and more prone to cracking, tearing and wrinkling[82]. This can lead to a more rapid deterioration of the insulating properties of protective gloves. Workers should therefore be encouraged to inspect their gloves for visual signs of damage and replace them immediately if necessary[82].
General requirements for all types of protective gloves are set out in EN ISO 21420[83]. This standard specifies requirements for the ergonomics, sizing, construction, visibility, maintenance and comfort of protective gloves. It also includes a dexterity test with five levels of performance where 5 is the highest level. In addition, EN 511[84] describes the requirements for protection against cold. The standard sets performance levels for thermal insulation (convective cold) and thermal resistance (contact cold). Both protective properties are divided into four classes (4 = highest protection).
Other PPE
In addition to clothing and gloves, PPE against the cold also include footwear and head protection. Footwear should be insulated, slip-proof with an appropriate fit (adapted to multiple pairs of socks). Head protection includes a cap or balaclava to protect the ears, neck and part of the face. The cap or balaclava should fit well with other PPE such as safety helmet, face mask, eye or hearing protection. Goggles are recommended in strong winds to prevent freezing of the eye cornea[12]. Respiratory protection (breathing mask with preheated air) may be required in circumstances where large volumes of very cold air are inhaled (e.g. heavy work below -15 to -20˚C)[19].
In some circumstances heated PPE (clothing/gloves/footwear with embedded heating elements) can further improve thermal comfort. All battery-operated heated PPE must comply with electrical safety standards and be lightweight to avoid fatigue.
Impact of PPE
It should be noted that PPE can impact performance, physical strain as well as create additional risks:
- Some PPE is very tight-fitting which increases the risk of frostbite[85].
- Highly insulating PPE worn during heavy work can create a warm microclimate that can induce sweating. As soon as the physical activity is stopped, the sweat begins to evaporate, causing further cooling, which can contribute to cold stress[85].
- Bulky and heavy protective clothing can affect performance by restricting movement, increasing muscle strain and workload[12].
- Protective gloves can reduce dexterity and grip (see also above).
- Earmuffs and balaclavas can impair hearing making it more difficult to understand conversations or to hear acoustic cues[52].
- Balaclavas can reduce peripheral vision, making it difficult to navigate spaces and identify hazards[52].
- Physical bulk of PPE can reduce manoeuvrability and may restrict manual handling[52].
Conclusions
Working in the cold is common in many sectors, such as the food industry (temperature-controlled environments) or for outdoor workers, such as in construction, agriculture and some green jobs (cold weather conditions). Although climate change may lead to milder winters overall, cold spells could still occur in some regions and become more intense. Exposure to cold can lead to a wide range of health problems, impair physical and mental performance and increase the risk of occupational accidents. Protecting workers requires a structured approach based on a thorough risk analysis. Standardised measurement methods help to assess risks and provide a basis for prevention measures. Measures include both technical (e.g. adaptation of work equipment) and organisational (e.g. work/rest cycles). To further reduce residual risks, it is necessary to provide appropriate personal protective equipment.
