Climate change is altering the conditions UK employers need to plan for. Higher temperatures and changing rainfall patterns can affect how work is organised, whether equipment remains safe and how people reach or leave a site.
Many of the hazards are familiar. The practical question is whether existing precautions still provide enough protection when conditions become hotter, wetter or more demanding.
This guide examines the UK evidence connecting climate change and workplace safety, the risks employers should review and the steps that can help them prepare.
These figures describe different aspects of exposure. The London finding is regional, while the rainfall figure concerns the winter half-year. Neither establishes what will happen at an individual workplace.
Employers therefore need to connect wider trends to local conditions: buildings that overheat, drainage that struggles during downpours, coastal exposure and tasks involving sustained physical effort.
Heat stress occurs when the body cannot adequately control its internal temperature. According to HSE’s heat stress guidance, air temperature is only one factor. Work rate, humidity, air movement, nearby heat sources and clothing also affect the risk.
Symptoms can include difficulty concentrating, cramps, dizziness and fainting. Severe heat illness can become life-threatening.
Physical work and restrictive protective clothing can make it harder to lose heat. HSE identifies hot industrial processes, catering kitchens and laundries among the environments where heat stress can occur. Hot weather can add to those existing exposures.
The UK Health Security Agency also highlights the risk to health and care staff wearing PPE. This makes overheating a relevant consideration for indoor workplaces as well as outdoor teams.
Following HSE’s advice for outdoor work, employers can consider moving demanding activities to cooler times, providing shade, increasing recovery breaks and ensuring access to cool drinking water.
For indoor work, HSE recommends measures such as shading windows, moving workstations away from heat sources, improving ventilation or cooling, and changing work arrangements.
Required PPE must continue to protect against the original hazard. Removing it to cope with heat may introduce a different danger. Suitable alternatives, shorter exposure periods or changes to the work may be needed.
Some workers will need additional consideration because of health conditions, medication, pregnancy or limited experience of hot conditions. Occupational health advice may be appropriate. Workers should also know how to recognise symptoms, report concerns and obtain help.
On 19 July 2022, London Fire Brigade dealt with widespread fires during exceptional heat. Its incident account records heat-related injuries to 16 firefighters, including two who needed hospital treatment.
A separate World Weather Attribution study found that human-caused climate change made the July heatwave at least ten times more likely.
Together, these sources document occupational harm during weather conditions made more likely by climate change. They do not establish that climate change was the sole cause of each injury. The case demonstrates why physical workload, protective clothing and recovery arrangements need attention during extreme heat.
On construction sites, water can alter excavation conditions and place additional demands on supports. HSE’s excavation guidance requires attention to groundwater and surface water, and inspections after events that could affect strength or stability.
A previous inspection cannot establish that an excavation remains safe after conditions change. Competent reassessment may be needed before work resumes.
Flooding can also leave contaminated water and damaged electrical installations. UKHSA’s flood recovery guidance identifies risks from sewage and other contaminants, and the need for appropriate electrical checks.
Recovery work deserves its own assessment. Fuel-powered generators used in enclosed spaces, for example, can expose people to carbon monoxide. Water receding does not by itself establish that premises or equipment are safe to use.
A train derailed near Carmont in Aberdeenshire on 12 August 2020 after striking material washed onto the track. The Rail Accident Investigation Branch recorded 51.5 mm of rain in approximately three hours. It found that drainage and associated earthworks had not been constructed according to their design.
The driver, conductor and a passenger died. The Office of Rail and Road also identified failures in drainage management and arrangements for responding to extreme weather.
The investigation establishes rainfall-related safety failures; it does not establish that climate change caused that particular downpour. Its relevance is the need to check whether infrastructure and operating decisions can cope with intense rainfall.
Wildfire deserves proportionate consideration for land-based work, emergency response and premises near vegetation.
A peer-reviewed study of summer 2022 found that human influence made the UK’s very high fire-weather conditions at least six times more likely. It examined weather affecting fire danger, including how fires could spread or intensify once ignited.
The finding does not mean climate change started individual fires or that every workplace now faces the same risk.
UKHSA identifies injuries and harmful smoke exposure among the health consequences. Smoke can affect people beyond the immediate fire area.
Where exposure is relevant, employers should consider nearby vegetation, activities that could introduce ignition sources, warning arrangements and routes to safety. Changes may include postponing exposed work or relocating activities when a nearby fire or smoke makes conditions unsafe.
Longer-term decisions need to account for conditions expected during the life of a building, installation or operating plan.
The Climate Change Committee’s 2026 assessment of UK climate risk identifies approximately 2°C of global warming above pre-industrial levels by 2050 as the expected trajectory under current emissions pathways. This is a conditional projection, not a guaranteed outcome.
Three findings are particularly relevant:
- Extreme heat is a near-term planning concern. A 2025 Met Office study estimated that the cumulative chance of another UK day above 40°C reaches approximately 50% by 2035. Its calculation starts in 2023 and assumes the recent increase in likelihood continues.
- Drier summers can still contain intense downpours. Met Office projections indicate wetter winters and generally drier summers, with summer rainfall becoming more intense when it occurs.
- Heat and flood exposure are expected to increase. Under its mid-century warming context, the CCC projects hotter summers and greater risks from river, surface-water and coastal flooding.
For employers, this supports reviewing cooling capacity, drainage and the positioning of vulnerable equipment when refurbishment or replacement is planned. Day-to-day decisions should still respond to forecasts, inspections and actual working conditions.
In Great Britain, Regulation 3 of the Management of Health and Safety at Work Regulations 1999 requires employers to assess work-related risks. Assessments must be reviewed where there is reason to suspect they are no longer valid or a significant change affects them.
Weather-related changes can make such a review necessary. A useful assessment connects each exposure to a task, identifies who could be harmed and specifies what action is needed.
Review workplace experience alongside forecasts and local risk information. Useful evidence includes overheating complaints, water entering buildings, repeated drainage problems, interrupted access and previous near misses.
Involve workers and contractors who know how conditions affect the job. HSE’s risk assessment guidance recommends consulting employees and considering non-routine activities such as maintenance and cleaning.
Include people arriving at, leaving or moving between work areas. A usable work area may still be unsafe to operate if its access or evacuation route is affected.
The following examples can help structure a workplace weather review. They need adapting to the site and task.
Assign responsibility for monitoring conditions, authorising changes and telling affected workers. Instructions should specify the action, who is responsible and when it takes effect.
For example, a warehouse heat review might identify that a physically demanding task needs to move to an earlier shift, with suitable breaks and a cooler recovery area. The supervisor then needs a way to check that the revised arrangements are effective.
Decide in advance who can authorise restart and what evidence they need. Depending on the event, this could involve inspections of excavations, electrical systems, access routes or other affected equipment.
Brief workers and contractors before restarting. Record changes to the assessment and working method, and check that the necessary precautions are in place.
For construction activities, this should connect with the arrangements for reviewing RAMS when conditions change.
HSE states that there is no general maximum workplace temperature. In Great Britain, employers must still assess temperature risks and provide a reasonable indoor working temperature. Action should reflect the task and exposure; workers do not need to wait for a record temperature before raising concerns.
A warning’s colour alone cannot determine whether a particular task is safe. Met Office warnings combine expected impacts with their likelihood. Read the warning details, assess the affected work and follow relevant safety limits and official advice. Change or stop activities where the risks cannot be adequately controlled.
Human Focus Risk Assessment Training explains how to identify hazards, evaluate risks, select precautions and review findings. It can help managers, supervisors and employees understand the process used to assess changing workplace conditions.
Training should be applied alongside workplace knowledge, suitable instruction and competent advice where needed.
