How to manage heat stress at work

Published 18th July 2022

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Most of us might enjoy temperatures in the 80s whilst on holiday around the Mediterranean … but that kind of heat is far more tolerable when there is access to a pool and the choice of clothing is your own!

So what can we do to keep cool and stress free this week?

Managing for very hot weather

In most years, the very hot summer weather sits to the south of the UK and – whilst warm summer days are not uncommon – temperature levels are usually more manageable than those forecast for this week; as a result, many UK homes and businesses are unprepared for rare spells of extreme heat. 

There is no legal maximum temperature that means a workplace is ‘too hot’ – employers are required to maintain a working temperature that can be considered reasonable and must make sure their employees are aware of any risks to their health arising from working in higher than usual temperatures, then take steps to minimise the risk of anyone being seriously affected as a result of the work they do; homeworkers should not be overlooked when considering this issue, nor should anyone with a heath condition that makes them more vulnerable as a result.


Working outside

Outside work in hot weather has two major safety / health implications – exposure to high levels of ultra violet (UV) light and higher than usual temperatures. Not every trade can achieve all of the following, but these are some of the working practices that should be adopted wherever practical;

  • Move start times so that workers can do more work in cooler temperatures.
  • Plan work so that as much as practically possible is conducted in the shade.
  • Allow workers regular breaks in cooler areas.
  • Allow workers to rehydrate regularly, with ready access to fluids.
  • Provide suitable clothing that protects workers from hazards and UV exposure.
  • Sunscreen is provided for areas of the body not covered by clothing.
  • Consider Permits to Work that limit working times as a condition of their issue.

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Working inside

Not every business is fortunate enough to have air conditioning – if you do have that option, make sure your system is regularly serviced so that it runs effectively when needed.  Workspaces without the benefit of air conditioning can make the workplace more comfortable by;

  • Moving start times so that workers can do more work in cooler temperatures.
  • Only opening windows when the outside air temperature is cooler that the workplace – this allows heat to escape.
  • Keeping windows closed when the outside air temperature is warmer than the workplace to minimise heat build-up.
  • Close any blinds or other window coverings to keep direct sunlight out of workspaces.
  • Supply fans to keep workers cooler in workspaces that are not air conditioned.
  • For buildings affected by having one or more areas in strong direct sunlight, allow workers to ‘hot desk’ or at least take regular breaks in cooler areas.
  • Allow workers to rehydrate regularly, with ready access to fluids.

Heat stress

Physical work in warm weather is unavoidable for many – for some trades, such as bakers and foundry workers, it can be an issue all year round; heat stress occurs when the body’s means of controlling its internal temperature starts to fail. Factors that can lead to heat stress include;

  • Air temperature.
  • Humidity levels.
  • Work rate required for the task.
  • The type / nature of clothing worn while working.
  • The size of the workplace and the ability for heat to dissipate from ‘hot spots’.

Heat stress affects people in different ways – an inability to concentrate, muscle cramps, heat rash, severe thirst, fainting and, most seriously heat exhaustion and heat stroke – heat stroke can result in death if not detected at an early stage. 

Wherever heat stress is a significant issue, relevant employees should have adequate instruction / information to help them recognise when they are at risk, how to minimise that risk and what action to take if they start to develop any of the symptoms listed above; if a significant residual risk remains after implementing as many control measures as practicable, you may need to monitor the health of exposed workers.

Further Assistance

It is worth bearing in mind that many UK workers will not be acclimatised to working in very hot weather – and doing so suddenly may throw up issues that were not evident in the normal, milder temperatures we are used to.

For most businesses, extremes of temperature can be managed by adapting existing risk assessments to allow for working when high temperatures are forecast but, if a significant number of employees are complaining about thermal discomfort, you should consider a separate risk assessment; likewise, a dedicated heat stress risk assessment needs to be conducted when heat stress factors are likely to be present.

If this alert has raised additional questions – or you have a Health and Safety law issue you would like assistance with – please do not hesitate to contact us.

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