• Alastair Gray

Working in High Temperatures – Health and Safety Advice

Updated: Jul 19


The current heatwave is making life unpleasant for many people but particularly those who have to work in premises that may already be hot and uncomfortable. Although it’s forecast to end soon, it’s highly likely that we will be facing more and so employers need to consider what can be done to make workplaces safe during extreme weather.

So, what does the law say about employer obligations?


Although there are regulatory limits for working in cold temperatures, this isn’t the case for hot temperatures. This is because some industries need high temperatures to operate and they would be prevented from doing so if the law said they couldn’t go over a certain temperature.


The HSE publishes a Workplace Regulations Approved Code of Practice (ACoP) that suggests a minimum of 16°C, or 13°C if the work being carried out is physical or strenuous. Of course, if the work has to involve lower temperatures, then these suggested minimums won’t apply.

It’s important to note that there is no legal requirement regarding these temperatures – they are guidelines only. However, what the law does say is that workplaces should be provided with clean, fresh air (Regulation 6 of the Workplace (Health, Safety and Welfare) Regulations 1992) and that measures should be put in place to keep the temperature at a “comfortable” level. This is sometimes known as “thermal comfort” and the HSE has produced a checklist that employers can use to assess whether this has been achieved.


Ultimately, the employer will know best how their business works and what is reasonable and appropriate. They should, however, take steps to create an environment where employees feel confident enough to raise their concerns about workplace conditions. They will be then able to have an open conversation on what can be done if the workplace becomes too uncomfortable to work in.


The risk assessment

A risk assessment is one of the foundations of good health and safety governance and this should already have been carried out, regardless of whether employees work indoors or outdoors. It will include the temperature of the working environment and the hazards of working in hot weather. If comments from employees indicate that there’s an issue that needs to be assessed, the risk assessment should clearly be revised.

Who will be affected?

All employees can be affected by hot weather. However, there will be people who are at more risk, including pregnant women, the elderly and people whose medical conditions mean they will be affected to a greater degree.


Employees working outside

Naturally, employees working outside will be affected by hot weather. The heat will have a significant effect but so will exposure to direct sunlight for a prolonged period without the appropriate safeguards. Hazards include:

  • heat rash;

  • severe thirst and dehydration;

  • sunburn;

  • fainting;

  • heat exhaustion;

  • heat stroke;

  • premature skin ageing;

  • skin cancer.

Controls and safeguards that can be implemented include:

  • Postponing or rescheduling work, if it’s possible to do so.

  • Encouraging more frequent breaks in shaded areas.

  • Making sure uniforms are made from breathable and moisture-wicking fabrics.

  • Providing shaded areas to work where possible.

  • Supplying cool drinking water (free of charge if possible).

When employees are working outside, they should:

  • wear a high factor sunscreen;

  • wear appropriate sun protective clothing;

  • drink plenty of water;

  • take regular breaks.

Additionally, they should get into the habit of checking any changes to their skin, such as looking out for new moles, or moles that change shape or colour, or bleed.


Employees who work indoors

Working indoors, out of direct sunlight and perhaps with air conditioning to make intensely hot days more bearable, may be thought comfortable enough by employers without further measures but there are options that can be deployed to increase the comfort level further:

  • Relax dress codes, especially for formal office wear like suits and ties.

  • Provide adequate cooling systems like fans or portable air-cooling units if there is no air conditioning installed in the building. Electrical safety and PAT should be taken into consideration when using such devices.

  • If workstations can be moved away from direct sunlight or heat sources, then this should be done. If that’s not possible or practical, then using barriers such as blinds to screen workers from the sun should be deployed.

  • If there’s an area of the building that’s cooler, then this could be designated as a break area to give employees a chance to escape the heat.

  • For many workers, breaks are something they overlook if their workload is high, but employers need to encourage regular breaks, particularly if the work generates heat in the employee.

  • It may also be an idea (where practicable) to consider adjusting working hours so that employees are not exposed to the sun at the hottest time of the day.

  • Hydration is vital in extremes of heat, and therefore, cool drinking water should always be made available.

  • Opening windows to permit airflow is often key to cooling an indoor workspace, so all windows should be checked to confirm they open.


Remote working

There has been advice for workers not to travel in London unless their journey is absolutely necessary; this is partly due to the risk to health of being in a cramped environment such as a train, bus or Tube in high temperatures, and partly because of the effect on rail infrastructure of the heatwave (with reports of rails buckling and trains reduced to half speed). Given the rise of hybrid and remote working since the end of the pandemic, the option of working from home during intense heat is now more practical than it might have been before 2020, and it is certainly something that employers should consider as an interim measure until the heatwave ends, and for future periods of intense heat.


Refusing to work in hot weather

Occasionally, an employee may feel that it is too hot for them to work and refuse to do so. If confronted by this situation, the employer needs to discuss the reasons for their refusal. This may identify areas where changes can be made to the working environment or revisions that need to be made to the risk assessment.

If those changes are made and the employee still refuses to work, then the employer may have to consider disciplinary measures, although all stages of the refusal, complaint and discussion should be recorded so that evidence is to hand if the case results in an employment tribunal claim.

If the changes can’t be made, or the employer does not change the working environment after the discussion, then the employee in question may have grounds for refusing to work.


Heatwaves are becoming more common, but they are still a rare occurrence and employers may not know how to navigate the legal and regulatory implications they bring. It is important that businesses obtain reliable legal advice early as this will increase their chances of avoiding future legal action against them.