working temperatures

Summer and the long-awaited sunshine – What’s the harm?

Many people enjoy the sunny weather, but extreme heat can cause serious health problems for your workforce. The difference between exposure at work and exposure at home or on holiday is that the employee has a choice when not at work.

Daren Lawson of Callidus looks at what employers can do to minimise exposure to the sun and how to stay cool in warm temperatures for outdoor workers.

Thermal Stress

In hot weather people get dehydrated and this can cause the body to overheat, seriously affecting an employee’s ability to function safely. Dehydration effects can be minimised by encouraging employees to drink cool water rather than tea, coffee or carbonated drinks frequently and in small volumes to compensate for losses due to sweating. They should be made aware that thirst is not a good indicator of dehydration as if you are thirsty you are already starting to suffer from the effects of dehydration.

What this means is that when working hard in hot weather employees should consume around 250 ml (half a pint) every 15 minutes or 500 ml (a pint) every 30 minutes.  Even if workers replenish the lost sweat with equal amounts of water, they may still be susceptible to dehydration due to salt losses caused by excessive sweating. Therefore, before they start work they should ensure that they are adequately hydrated.

The symptoms of heat exhaustion include headaches, dizziness, nausea and vomiting, muscle weakness or cramps, pale skin, and a high temperature. You should move the employee somewhere cool and get them to drink plenty of water or fruit juice. If you can, get them to take a lukewarm shower, or sponge themselves down with cold water.

Heatstroke can develop if heat exhaustion is left untreated, but it can also occur suddenly and without warning. Symptoms include headaches, nausea, an intense thirst, sleepiness, hot, red and dry skin, a sudden rise in temperature, confusion, aggression, convulsions and loss of consciousness. Heatstroke can result in irreversible damage to your body, including the brain, or death.

Sun Exposure

Too much sunlight is harmful to the skin. A tan is a sign that the skin has been damaged. The damage is caused by ultraviolet (UV) rays in sunlight.

If workers are outdoors for a long time their skin could be exposed to more sun than is healthy. Particular care is needed if they have:

  • fair or freckled skin that doesn’t tan, or goes red or burns before it tans;
  • red or fair hair and light-coloured eyes;
  • a large number of moles.

It is a common misconception that you can ‘feel yourself getting sunburnt’, solar UV cannot be seen or felt so it can damage the skin without us knowing it.

Short and long-term problems of too much UV radiation

The harm in the short term, is that even mild reddening of the skin from sun exposure is a sign of damage. Sunburn can blister the skin and make it peel.

Longer term problems can arise. Too much UV radiation from the sun or sunbeds can damage the genetic material (the DNA) in your skin cells. This can also speed up the ageing of the skin, making it leathery, mottled and wrinkled. If enough DNA damage builds up over time, it can cause cells to start growing out of control, which can lead to skin cancer.

Your body has ways of repairing most of the damage. But it is not perfect – some damaged DNA can be left behind. Your body’s attempt to repair this damage is what causes the painful symptoms of sunburn (Cancer Research UK).

The ‘shadow rule’ tells you when the sun is strongest. Holloway’s rule is a straightforward way to know when the sun is strong: the sun’s UV rays are strongest when your shadow is shorter than you. So that’s when you’re more likely to burn.

What can you do to protect yourself?

  • Keep your top on (ordinary clothing made from close woven fabric, such as long-sleeved work shirt and jeans stops most UV)
  • Wear a hat with a flap that covers the ears and the back of the neck.
  • Stay in the shade whenever possible, during your breaks and especially at lunch time.
  • Use a high factor sunscreen of at least SPF15 on any exposed skin.
  • Drink plenty of water to avoid dehydration.
  • Check your skin regularly for any unusual moles or spots. See a doctor promptly if you find anything that is changing in shape, size or colour, itching or bleeding.

The following free leaflets have been produced by HSE:

The following website also provides useful information:

What can employers do to minimise exposure to the sun for those who work outside?

Employers should identify solar UVR exposure hazards and introduce control measures to reduce exposure such as choosing the right protective equipment, clothing and skin care products, as well as advising employees on UV protection and how to check for early signs of skin damage, changes or abnormalities.

A risk assessment is required, identifying those trades that are at risk and developing control measures, such as;

  • Encourage workers to wear light coloured, cotton, clothing. Apply a no ‘bare back’ policy or minimum short sleeved shirts policy.
  • Provide shaded rest areas and plenty of drinking water.
  • Try to plan outdoor works that are exposed to direct sunlight to take place before 11am or after 3pm.

Provide suitable sun-block. There is considerable debate as to whether or not sun- block constitutes PPE, however the risks of burning or skin cancer are foreseeable and therefore control measures must be introduced.

Should you need further assistance with this subject or any other health and safety issue please do not hesitate to call Callidus on 0113 385 2740.