Heat stress at work
Aude Cefaliello is a Senior Researcher at the European Trade Union Institute (ETUI)
Climate change is creating new risks to which workers are exposed in unequal fashion. The first sectors to feel the impact of extreme temperatures, such as agriculture or construction, are also those with extremely precarious workforces. This impact will be complex, adversely affecting physical and mental health in both direct and indirect ways.
Applying the general principles of prevention to heat stress is possible but it will require a thorough overhaul of how work is organised and the adoption of European legislation that lays down a minimum protective threshold for all workers in Europe.
In 2022, 62,000 deaths in Europe were attributed to the summer heat. This figure, likely an underestimate, is only one among the many examples illustrating a growing challenge that we must address, namely the significant consequences of climate change for public health and the world of work.
Year after year, we have ‘record temperatures’, pushing us to the realisation that the ‘historic’ heatwaves of 20 years past have now become the new normal. The European Environment Agency forecasts a steady rise in average temperatures as well as increasingly frequent and intense heatwaves.
Each summer, workers die because of the intense heat, but they are also at risk from other aspects of climate change and ever more extreme weather conditions (flooding, storms, wildfires, etc.). The time for ‘crisis management’ is over; we must rethink how work is organised to ensure that workers do not lose their lives while they earn their living.
The change in our means of production and organisation is all the more important and urgent because climate change will not impact workers equally. If we do nothing, then the working conditions in sectors where workers are already exposed to physical danger, such as agriculture, construction or the emergency services, will deteriorate further.
According to Eurofound, 23% of workers in the European Union are exposed to high temperatures for at least a quarter of their working hours; that proportion climbs to 36% in agriculture and industry, and to 38% in construction. These sectors are also known for having precarious working conditions and recruiting more vulnerable workers (temporary work and employment of foreign nationals).
If (legal) safeguards are not sufficiently robust, these workers are likely to be the next victims of the heatwaves which, in the words of Eric Klinenberg, are ‘silent, invisible killers of silent, invisible people’.
The multi-faceted impact of global warming on workers’ health
Climate change will affect all workers in all sectors in all countries, but its impact will not necessarily be the same or have the same intensity across the board. First, there are key differences in people’s working environments.
The European Agency for Safety and Health at Work (EU-OSHA) stresses that outside workers are most vulnerable to climate change, although its repercussions will extend to all sectors, in particular the emergency services, water supply, energy, transport and construction. The frequency and nature of climate risks will also not be the same for everyone.
Outside workers (including those working in construction, agriculture or maintenance of public spaces) are most exposed to extreme climate conditions (intense heat, but also UV radiation), whereas those working in the emergency, rescue and cleaning/maintenance services often find themselves in high-risk situations because of climate crises such as floods, landslides, storms, droughts and wildfires. Here, a lack of structural resources could aggravate the situation given that climate emergencies will increase the need for this kind of assistance.
When it comes to heat, indoor workers whose jobs require physical effort (eg. in warehouses or on production lines) will also be affected. Rises in temperature and humidity increase the risks involved in these kinds of jobs. The impact on health can be immediate, ranging from cramp and oedema to loss of consciousness and even death.
However, studies also point to the long-term risk of exposure to intense heat and its potential to cause heart, kidney or liver damage. The negative consequences of heat exposure may also have more long-term effects in the form of chronic tiredness, sleep disturbances and temporary infertility (especially for men).
Where workers’ mental health is concerned, the INRS (the French National Scientific Research Institute) and ANSES (the French Agency for Food, Environmental and Occupational Health and Safety) note the greater psychosocial risks associated with global warming. The mere fact that heat is tiring and poses an additional cognitive strain (that can cause irritability or even violence) is a risk to workers (tension and conflict) when interacting with colleagues and non-colleagues alike.
Cognitive fatigue also increases the risk of accidents at work, especially because it reduces concentration and can lead to woolly decision-making in the work environment (posing extreme danger when driving or operating machinery).
As EU-OSHA has stressed in its guidance on heat stress, published in 2023, heat has not only direct (short-term and long-term) but also indirect effects on workers, through the exacerbation of existing risks such as air pollution, self-heating materials, the occurrence of biological agents, and exposure to chemical substances1.
Heat can also affect the application of certain OSH prevention measures, most notably the wearing of PPE, potentially even turning it into a risk itself.
In the absence of specific legislation on heat stress, there is no guarantee that employers will abide by the recommendations
OSH principles applied to heat stress prevention
Incorporating climate hazards into occupational risk assessments is emerging as a key issue in workers’ safety in Europe. The need to adopt sector-appropriate preventive measures, which acknowledge that the impact of climate conditions depends on the type of work concerned, underlines the importance social partner involvement in this issue.
Where heat-related risks are concerned, EU-OSHA’s recent guide shows that it is perfectly possible to implement a collective system of technical and organisational preventive measures within an individual organisation.
The principles already set down in the 1989 Framework Directive (Directive 89/391/EEC) on health and safety at work can also be applied to heat stress, for example the obligation of the employer to evaluate all workplace risks and to adopt (first collective then individual) preventive measures following an information and consultation process with the workers and/or their representatives.
Employers should evaluate the risks created by climate change, taking various factors into account, including a worker’s protective clothing, age and health. For heat exposure, biological differences should also be taken into account, given that some studies note that women may be less heat-tolerant than men.
According to EU-OSHA, the application of the existing obligation to develop a comprehensive, consistent policy to prevent heat stress should lead to the implementation of heat action plans, an early warning system and the implementation of safe working practices.
Risk assessment should be followed by the introduction of a hierarchy of controls, perhaps including emergency procedures and a ‘buddy’ system. Working in isolation poses a considerable risk in itself given that it is very difficult for someone to assess their own heat tolerance and that, if an incident occurs, assistance from a third party is vital for administering first aid and raising the alarm with the emergency medical services.
Additionally, the information that workers should receive on the dangers of heat stress should include descriptions to help them recognise the symptoms of heat-related injuries and illnesses, measures to reduce the risk, acclimatisation procedures and procedures to follow in the event of heat-related illness. However, in the absence of specific legislation on heat stress, there is no guarantee that employers will abide by the recommendations.
A legislative void
The other issue is that the measures recommended by EU-OSHA require the option for workers to adjust their time schedules and a needs-based reduction in labour intensity, regardless of economic pressures, which may require a larger workforce.
Currently, and especially in sectors with a vulnerable workforce, the reality of power differentials is obviously unlikely to lead workers to behave in a way that prioritises their health.
Consequently, in France, the sociologist Annie Thébaud-Mony, a specialist in occupational health, is advocating express reference to heat-related risks in the Labour Code, including changes to working schedules during periods of high temperatures. Nonetheless, no express provisions have yet been adopted, despite evidence of many heat-related health risks.
Despite this, some countries, such as Spain, have taken measures to reorganise work schedules during intense heat. In Greece, the guards working in the Acropolis have secured an adjustment to their time schedules that avoids their working in the afternoon during heatwaves. This flexibility is vital to protect workers’ health but should apply across the board so that all sectors can benefit.
Legislation varies considerably from one country to another in Europe. In Spain, measures based on weather alerts are in place to prohibit outdoor working in periods of extreme heat. In Portugal, the temperature of a workplace must by law be between 18 and 22 degrees Celsius and have a specific humidity management system.
In the Belgian ‘law on thermal environmental factors’, targeted at both heat and cold, action is mandatory when the legal occupational exposure temperature limit is exceeded (according to the Wet Bulb Globe Temperature index, which strictly speaking considers not just temperature but also other elements like humidity and wind).
Although there are recommendations in Germany, there is no legal occupational exposure limit value on heat stress. The problem is that today’s Berlin is tomorrow’s Madrid. Legislation needs to be harmonised to provide a minimum protective threshold for all workers in Europe.
In this ‘legislative void’, national case law has begun to provide some answers regarding ad hoc protection for workers. In 2015 in France, roofers exercised their ‘right to withdraw’ in the event of serious, imminent heat-related danger and stopped working during a heatwave.
In Italy, a 2015 ruling found that where working conditions were unsafe or temperatures were ‘prohibitive’, workers have the right to stop working with no loss of earnings or danger of dismissal.
True worker protection requires a paradigm shift
Today, we face a political emergency. From a European legislative standpoint, there is a genuine difference between indoor jobs and outside jobs, with outdoor workers excluded from the protective scope of some directives.
The sectors most affected are also those where precariousness is highest; we are once again in danger of sweeping the risks these workers face under the carpet. We must resist the discourse and fatalistic narrative that says, in effect, that nothing can be done, that it’s an ‘occupational hazard’, or all part of the job.
The fact that conditions will become increasingly extreme is unfortunately a reality for the coming years, but we have a choice as to how we are going to respond collectively and how we decide to protect (or let down) the workers concerned.
But ensuring that workers are genuinely protected means revising economic needs and objectives downwards. We must restore human beings to the heart of how work is organised. The current neoliberal momentum means that we cannot maintain production and also ensure workers’ health.
In other words, workplaces must see either an increase in available resources or a reduction in the pressures of work. All the recommendations point in one direction: the best preventive measures require workers to be able to regulate their own hours and tasks so that they can alternate rest periods with work.
This means giving some autonomy back to workers; but that autonomy will only be genuine if it is exercised in an environment where economic pressures and power are controlled and attenuated.
It would be naïve to assume that workers will behave in a way that prioritises their own health and their colleagues’ if doing so puts their jobs at risk. In view of climate change, we need to adopt measures that will enable workers to be heard, empowered, recognised and protected.
This article is part of a comprehensive dossier published by the European Trade Union Institute (ETUI) in HesaMag #28 on Workers and the climate challenge.
