Safety Bulletins

Working safely in hot conditions

There's no law for maximum working temperature, or when it's too hot to work. However, employers must keep workplaces at a comfortable temperature.

HSE's temperature website has practical guidance on what you can do to manage the risks so people can work safely in hot conditions, including managing workplace temperature, outdoor working and heat stress.

HSE is also advising employers to act now to make sure their workplaces are ready for warmer weather in the future. 

Working in warm temperatures can mean we sweat more and there is the risk of dehydration and heat illness if sufficient fluids are not consumed to replace those l

Heatstroke and heat exhaustion

Heatstroke and heat exhaustion both occur after prolonged exposure to high temperatures and are far more likely when physical exertion has taken place. Although caused by the same factors, heat exhaustion is not treated as serious and once cooled down should get better. Heat stroke, however, is serious and should be treated as an emergency.

People with heatstroke generally look unwell and might have difficulty breathing.  They may also be confused and irritable.  Drink plenty fluids and move to somewhere cool, if possible cool the skin by placing wet clothing on it and call 999!

Heatstroke is when the body is no longer able to cool itself and a person’s body temperature becomes dangerously high.  It is much more dangerous than merely feeling hot and bothered and can kill in as little as 30 mins so it’s vital to recognise the warning signs and take action when necessary. This may require an emergency call on 999.  Do not let themselves home or to the doctors/ hospital if they’re unwell.

There are various stages which people are likely to go through before they reach the critical stage of heatstroke, and it’s vital to be aware of these warning signs. 

First, you might spot symptoms of heat exhaustion which can include:

  • Heavy sweating
  • Rapid breathing
  • Nausea
  • Fast, weak pulse
  • Light headedness
  • Feeling of fatigue

Aim to avoid the heat of the day, working in the cooler earlier morning/evening; shorten the days for physical tasks; In hot weather and sun exposure don’t forget your sunscreen!

Heat exhaustion is not a life threatening condition itself, but it can be a precursor to heatstroke, which is far more serious if action isn’t taken. Signs of heat exhaustion include:

  • Headache
  • Dizziness and confusion
  • Loss of appetite and feeling sick
  • Excessive sweating and pale, clammy skin
  • Cramps in the arms, legs and stomach
  • Fast breathing or pulse
  • Temperature of 38⁰C or above
  • Intense thirst

The following steps can be taken to cool someone down:

  • Move them to a cool or shaded place
  • Remove unnecessary clothing to expose skin for cooling (sweating cools the body and works through the evaporation across the skin)
  • Get them to lie and raise their feet slightly
  • Get them to drink plenty of water (Sports or rehydration drinks are ok too)
  • Cool their skin – spray or sponge them with cool water and fan them. Cold packs around the armpits or neck are good too.

Stay with them until they are better.

They should start to cool down and feel better within 30 minutes. If not consider that it may be more serious and medical attention could be required and may even require an ambulance. Do not let them drive themselves home if they’re unwell!

Tips to help keep hydrated:

  • Drinking water regularly throughout the day is more effective than drinking large amounts infrequently. 
  • Being hydrated before work makes it easier to stay hydrated throughout the day.
  • Dehydration is a primary contributor to heat exhaustion so if working in warm conditions, it is best to drink water before you start to feel thirsty.  This will mean you are not behind in fluid replacement when you start to sweat.
  • It is recommended that you drink one cup of water every 15-20 minutes if working in hot conditions.
  • Drinking fluids after you have stopped working can help the rehydration process and place less strain on your body from dehydration. 
  • Water will almost always maintain your hydration when working in heat, as long as you eat regular meals to replace salt lost in sweat.
  • Soft drinks, tea and coffee all contribute to your fluid intake; however energy drinks can contain high levels of caffeine which can add to the strain already on your heart when working in hot conditions and are best avoided.
  • Alcohol can cause dehydration and, if consumed within 24 hours of working in heat, can increase the risk of heat illness



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