What are WHO & WMO’s Concerns for Extreme Heat and Workers?

"Since systematic scientific assessments began in the 1970s, the influence of human activity on the warming of the climate system has evolved from theory to established fact," says the Intergovernmental Panel on Climate Change.

The World Health Organization (WHO) and the World Meteorological Organization (WMO) have collaborated to publish a report, climate change and workplace heat stress, highlighting guidance on how to face the growing global health challenges when it comes to extreme heat on workers.

Adapting to climate change

“Globally, population exposure to heatwaves will continue to increase with additional warming, with strong geographical differences in heat-related mortality affecting those with the least resources and without additional interventions and adaptation,” the WMO says.

As climate change is expected to drive more extreme heatwaves, many workers are regularly exposed to dangerous heat conditions.

The pair state that they are “already feeling the health impacts of rising temperatures, in particular, manual workers in sectors such as agriculture, construction and fisheries.”

If increasing heat episodes are becoming more frequent, it is predicted that health issues may become more common for vulnerable populations in developing countries, such as children, older people, low income individuals and vulnerable people.

“Heat stress is already harming the health and livelihoods of billions of workers, especially in the most vulnerable communities,” says Dr Jeremy Farrar, WHO Assistant Director-General, Health Promotion, Disease Prevention and Care. 

“This new guidance offers practical, evidence-based solutions to protect lives, reduce inequality, and build more resilient workforces in a warming world.”

Inside the report

The report draws on five years of data, research and evidence with WMO reporting that 2024 was the hottest year on record.

Daytime temperatures of 40°C and over are said to become “increasingly common”, proving that immediate action is needed if extreme weather events are to be tackled and diminished.

“Occupational heat stress has become a global societal challenge, which is no longer confined to countries located close to the equator, as highlighted by the recent heatwave in Europe,” says Ko Barrett, WMO Deputy Secretary-General. 

“Protection of workers from extreme heat is not just a health imperative but an economic necessity.”

The report outlines key issues related with health impacts of extreme heat:

• The frequency and intensity of extreme heat events have risen sharply, increasing risks for both outdoor and indoor workers
• Worker productivity drops by 2–3% for every degree above 20°C
• Health risks include heatstroke, dehydration, kidney dysfunction and neurological disorders – all of which influence long-term health and economic security.
• Approximately half the global population suffers adverse consequences of high temperatures.

Both WHO and WMO call for the implementation of occupational heat action plans, tailored uniquely to industries and regions.

The pair state that this plan of actions needs to be “developed in collaboration with employers, workers, unions and public health experts.”

Can we adapt to extreme heat?

The report outlines clear paths for governments, health authorities and employers when it comes to mitigating the increasing risks of extreme heat on workers.

One plan of action is to develop occupational heat-health policies, consisting of tailored plans and advisors that take into consideration local weather patterns, specific jobs as well as the vulnerability of the workers.

A key focus should be to focus on vulnerable populations,  says WHO and WMO, giving special attention to:

• Middle-aged and older employees
• Individuals with chronic health issues
• People with lower fitness levels – these individuals can be more prone to effects of heat stress.

A prime way of moving forward is to educate and raise awareness of the effects of working in extreme heat.

First responders, health professionals, employers and workers should be educated on recognising and treating heat stress symptoms – these are often misdiagnosed according to WHO and WMO.

Engaging all stakeholders from workers and trade unions to health experts and local authorities in the co-creation of heat-health strategies that are locally relevant and widely supported is stated as a plan of action in the report.

Designing solutions that are effective, practical, affordable and environmentally sustainable will help to ensure that policies can and will be implemented at scale.

Adopting technologies that can safeguard health as well as maintain productivity could help individuals adapt to the extreme heat.

Supporting further research and evaluation could help strengthen the effectiveness of occupational heat-health measures and ensure maximum protection for workers worldwide, states WHO and WMO in the report.

“This report represents a critical milestone in our collective response to the growing threat of extreme heat in the world of work,” says Joaquim Pintado Nunes, International Labour Organization’s Chief of Occupational Safety and Health and the Working Environment. 

“Aligned with the ILO’s mandate to promote safe and healthy working environments as a fundamental right, it offers robust, evidence-based guidance to help governments, employers and workers confront the escalating risks of climate change. 

Together with WHO and WMO, we call for urgent, coordinated action to safeguard the health, safety and dignity of the more than 2.4 billion workers exposed to excessive heat worldwide.”

The report and technical guidance by WHO and WMO complement the findings of the recent ILO reports which highlight that more than 2.4 billion workers are exposed to excessive heat globally, resulting in more than 22.85 million occupational injuries each year.