13 Jun 2024

Impact of heat in the workplace

heat in the workplace

Global warming has shown that we are experiencing more extreme weather conditions. The Met Office reports that we have had the warmest years in the last 2 decades (despite the rain in the UK!)

The International Labour Organisation (ILO) (Increase in heat stress predicted to bring productivity loss equivalent to 80 million jobs | International Labour Organization (ilo.org))  states that ‘By 2030 the equivalent of more than 2% of total working hours worldwide is projected to be lost every year, due to extreme weather conditions.’ This may not seem a lot but this equates to the production loss of 80 million full-time jobs.’

Who is at risk of excessive heat in the workplace

Obviously, some countries are more at risk. Some occupations are more affected, such as agriculture, construction, factories, workshops etc, dependant on the level of physical exertion involved and time spent outside. It is predicted that agriculture will make up 85% and construction 60% of the losses.

Regulation 7 of The Workplace 1992 (health safety and welfare regulations) ‘requires employers to provide a reasonable indoor temperature in the workplace. This depends on the work activity and the environmental conditions.’ (Source: HSE.gov.uk)

There is no maximum illegal temperature to work in or strict workplace temperature to adhere to. However every employer has their own responsibility for the wellbeing of their employees. This includes reducing their risk of heat stress and related illnesses.

What is heat stress?

Heat stress occurs when the body’s means of controlling its internal temperature starts to fail. As well as air temperature, factors such as work rate, humidity and clothing worn while working may lead to heat stress.’ (Source HSE.gov.uk).

It is also worth taking note that heat stress is not just about air temperature. It is also influenced by humidity, pace and type of work and clothing (including if PPE is worn). Some employees will be affected by this more than others, due to age, weight, and existing medical conditions. Some may acclimatise to the hotter conditions quicker than others.

When the body is under heat stress, it can cause additional workplace hazards. This includes lack of concentration and confusion so higher risk of injuries, alongside occupational heat related illness and productivity loss.

Types of Heat Related Illness (HRI)

Heat cramps

These are muscle cramps, specifically caused by lack of water and sodium (salt) that are needed by your body to work. This is especially dangerous when operating machinery.

Heat exhaustion

Also occurs due to dehydration and salt deficiency. It can cause muscle cramps, headaches, nausea or vomiting, dizzy and fainting spells, and skin clammy to the touch.


Heatstroke is very serious and can cause permanent organ damage or death. Symptoms include skin that is very red and hot to the touch, confusion, visual disturbances, headache, lack of sweating, seizures, or lack of consciousness.

What can employers do to reduce the risk of heat in the workplace?

1.Carry out a risk assessment

This should be part of your OSH management system. Identify heat related hazards and those employees most at risk. Define safe working practice procedures in extreme temperatures. Document and ensure all employees have been clearly communicated to and understand the proper precautions. Click here for more information on risk assessments.

2. Reduce elements of heat where possible

This may mean offering flexible working patterns so employees are not working throughout the hottest times of the day.

Consider job shares or temporary assignments so those employees most at risk are accommodated.

Introduce additional mechanical elements so there is less human intervention.

Move workstations to cooler areas or invest in air conditioning/air ventilation/air movement etc and cooling devices on machinery if applicable.

Set up structures to offer shade for outside workers.

Enforce extra breaks maybe produce a recommended timetable.

Consider changing the dress code or purchasing PPE that is made from more breathable fabrics or have inbuilt cooling mechanisms.

Provide plenty of cool drinks, sunscreen, and cool rest areas.

3) Educate workers on heat stress

It is extremely important that all workers know the importance of looking after themselves and looking out for their colleagues. They should all have relevant training in heat stress, including symptoms to look out for and what to do if you notice a colleague with these symptoms. Emphasis should be placed on taking ownership for their own wellbeing by ensuring they are hydrated, taking regular breaks, wearing hats/sunscreen etc.

Where possible eliminate or reduce lone working. Always provide regular check-in systems and procedures if workers are on their own.

4) Monitoring and improvements

Although this risk may only be for a few weeks of the year, it is no less important to ensure regular monitoring of temperatures, humidity, checking in on staff wellbeing and identifying areas for improvement.

Employers play a critical role in implementing effective measures to reduce the impact of heat stress. Which involves developing policies, utilising technology, and behavioural change.

If you would like any advice on managing heat as a risk factor in the workplace or help with risk assessments, please feel free to contact us on 01527 833834 or email info@sentinelsafety.co.uk

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