Temperature is often treated as a comfort issue, but in many workplaces it can become a significant health and safety risk. Excessive heat, cold working conditions, poor ventilation, physical work, PPE, humidity, radiant heat and outdoor weather can all affect a worker’s health, concentration and ability to work safely.
Introduction
Working at temperature can create health, safety and welfare risks if it is not properly managed. This includes work in hot, cold or uncomfortable conditions, whether caused by the weather, the building, work equipment, work processes, protective clothing or the physical demands of the job.
UK health and safety law does not set a single maximum workplace temperature. Instead, employers must provide a reasonable working temperature and assess the risks that hot or cold conditions may create. There is no legal maximum working temperature because every workplace is different, but heat and cold must still be managed as workplace hazards.
Main Legal Duties
The main legal requirement is found in The Workplace (Health, Safety and Welfare) Regulations 1992. During working hours, the temperature in all workplaces inside buildings must be reasonable. Heating and cooling methods must not expose workers to harmful or offensive fumes, and excessive effects of sunlight on temperature should be avoided where practicable.
HSE guidance, based on the Approved Code of Practice, states that indoor workplace temperatures should normally be at least 16°C, or 13°C where much of the work involves rigorous physical effort. These figures are not absolute legal limits, but they provide a recognised benchmark for general indoor working conditions.
Employers also have wider duties under health and safety law to protect employees and others from risks to their health, safety and welfare. In practice, this means employers should:
- identify hot, cold or uncomfortable working conditions
- assess whether they may create a risk to health, safety or welfare
- introduce suitable controls
- consult workers and respond to concerns
- review arrangements when the workplace, weather or work activity changes
Scope and Application
Temperature duties apply across many workplaces, including offices, warehouses, factories, workshops, construction sites, kitchens, laundries, cold stores, outdoor work areas and process environments.
Temperature issues may arise from the general working environment, such as poor heating, inadequate ventilation, solar gain, cold draughts or heatwaves. In other workplaces, the risk is created by the work itself, such as hot machinery, industrial processes, chilled or frozen products, heavy physical work, outdoor work or PPE that restricts heat loss.
Employers should consider the actual conditions workers face, not just the air temperature. Thermal comfort depends on a range of factors, including air movement, humidity, radiant heat, clothing, PPE, workload and individual differences.
Working in Hot Conditions
Hot working conditions can lead to heat stress, dehydration, fatigue, loss of concentration and, in severe cases, heat exhaustion or heat stroke. Heat stress can occur indoors or outdoors and may be caused by high air temperature, radiant heat, humidity, heavy physical work, direct sunlight, poor ventilation or protective clothing.
Employers should assess heat stress risks and introduce suitable controls where workers may be exposed to hot conditions. This is particularly important during heatwaves, in hot industrial environments, in outdoor work, and where workers are carrying out strenuous tasks or wearing PPE.
Suitable controls may include:
- reducing heat at source or improving ventilation
- providing local cooling, shade or cooled rest areas
- rescheduling work to cooler times of the day
- increasing rest breaks
- giving workers access to cool drinking water
- reviewing PPE where it increases heat strain
- training workers to recognise early signs of heat stress
For outdoor work, employers should also consider shade, more frequent rest breaks, safe removal of PPE during rest periods where appropriate, and arrangements for workers to report symptoms early.
Working in Cold Conditions
Cold working conditions can affect health, comfort and safety. Workers may experience reduced dexterity, slower reaction times, fatigue, discomfort and reduced concentration. In more severe conditions, cold exposure may increase the risk of cold stress or hypothermia.
Cold temperature risks can arise in refrigerated environments, cold stores, loading bays, unheated buildings, outdoor work, maintenance work and work involving wet or windy conditions. Where cold temperatures are unavoidable because of the nature of the work, the employer should still reduce exposure as far as reasonably practicable.
Controls may include:
- local heating or warm work areas where possible
- suitable insulated or weatherproof clothing
- gloves and footwear appropriate to the task
- heated rest facilities
- task rotation and limits on exposure time
- warm up breaks
- arrangements for drying wet clothing
- supervision and early reporting of symptoms
In food environments involving chilled and frozen products, temperature requirements may need to be met through controls such as localised chilling, warm workstations, protective clothing, heated rest facilities and task rotation.
Ventilation, Welfare and Drinking Water
Temperature management should be considered alongside ventilation and welfare. Employers should provide good ventilation, a reasonable working temperature, suitable lighting, enough space, suitable workstations and adequate welfare facilities.
Where workers are exposed to heat, access to drinking water is particularly important. Workers in hot conditions lose water through sweating, so employers should provide cool water and encourage workers to drink small amounts frequently.
Welfare arrangements may also need to include suitable rest areas, warm areas for cold work, shaded areas for outdoor work, changing or storage facilities for clothing, and arrangements for recovery from heat or cold exposure.
Risk Assessment
Temperature risks should be considered as part of the employer’s general risk assessment. A suitable assessment should look at the work activity, the workplace, the workers affected and the conditions likely to be encountered.
Relevant factors may include:
- temperature, humidity, air movement and radiant heat
- physical workload, PPE and work clothing
- work duration, rest breaks and access to drinking water
- outdoor weather, hot processes or cold environments
- individual worker vulnerability
- worker feedback or complaints
The assessment should be reviewed when conditions change, such as during heatwaves, cold weather, changes to work processes, changes to PPE or changes in worker health.
Vulnerable Workers
Some workers may be more vulnerable to hot or cold conditions. This may include new workers, young workers, pregnant workers, older workers, workers with certain medical conditions, workers taking medication that affects temperature regulation, or workers who are not acclimatised to the conditions.
Employers should take account of individual circumstances where temperature could create increased risk. This may involve reviewing the risk assessment, adjusting work patterns, increasing supervision, providing additional breaks or seeking occupational health advice where appropriate.
Worker Consultation and Reporting
Temperature issues should not be managed only by taking readings. Employers should consult workers and safety representatives where appropriate, as workers can often identify practical problems such as hot areas, cold draughts, poor ventilation, unsuitable PPE, lack of drinking water or rest areas that are not effective.
Workers should be encouraged to report symptoms of heat stress, cold stress or thermal discomfort early. Early reporting allows employers to respond before the issue becomes more serious.
Enforcement and Penalties
The Workplace (Health, Safety and Welfare) Regulations 1992 are enforceable health and safety regulations. Where employers fail to provide a reasonable workplace temperature or fail to manage risks from hot or cold conditions, enforcement action may be taken by the relevant enforcing authority.
Depending on the workplace, this may be the Health and Safety Executive or the local authority. Enforcement may include advice, improvement notices, prohibition notices or prosecution in serious cases.
Review
UK health and safety law does not set a fixed maximum temperature for work, but this does not mean employers can ignore hot conditions. Employers must provide a reasonable indoor working temperature and manage temperature related risks through risk assessment and suitable controls.
For most indoor workplaces, HSE guidance identifies 16°C as the normal minimum temperature, or 13°C where much of the work involves rigorous physical effort. However, employers must also consider heat stress, cold stress, outdoor conditions, ventilation, welfare, PPE, workload and the needs of vulnerable workers.
The practical aim is to ensure that working conditions remain safe, healthy and reasonable. Temperature should be monitored, worker concerns should be taken seriously, and controls should be reviewed when the weather, workplace or work activity changes.