Summer can mean that the heat is on for many workers spending their days outdoors, in poorly-ventilated offices or dressed in heavy-duty protective clothing. People who work workers should ensure that they are protected against damaging ultraviolet (UV) rays in sunlight that can cause skin cancer.

The body is good at maintaining a general average temperature of about 37°C. In hot weather the body sweats, and this sweat then evaporates to cool the skin. But when the outside temperature is hotter than the body, or when there is high humidity and the sweat cannot evaporate fast enough, a number of heat-related health problems may result. The main risks are dehydration (not having enough water) and overheating (which can make symptoms worse for those with health conditions or might cause people to develop heat exhaustion or heat stroke).

Heat and health problems

Extremes of heat can cause problems for people with pre-existing health conditions like diabetes, heart disease or high blood pressure. Heat waves (defined as a five-degree rise in temperature of more than five days compared to the expected average temperature) can result in a peak in the death rate (largely among the elderly and infirm). However, anyone working in unusually high temperatures can be susceptible to:

Heat stress

This can develop when the body’s cooling system is limited by outside temperature, humidity, physical work rate and work clothing. People most at risk are those working in intensely hot environments (e.g. glass works, foundries, mines, bakeries and laundries) and hot summer weather can increase the danger of heat stress. Symptoms can include:

  • an inability to concentrate;
  • muscle cramps;
  • rash;
  • severe thirst;
  • heat exhaustion
  • heat stroke.

Heat exhaustion

This is when the person becomes very hot and generally unwell, and develops some of the symptoms listed below. It can develop quickly over a few minutes, or develop gradually over hours or days. If left untreated, heat exhaustion can become heat stroke. Symptoms of heat exhaustion can include:

  • tiredness and weakness;
  • feeling faint or dizzy;
  • heavy sweating;
  • intense thirst;
  • nausea;
  • headache;
  • muscle cramps;
  • a fast pulse;
  • urinating less often and having much darker urine than usual.

Heat stroke

People experiencing heat stroke are often unable to see how serious their problem is and it is colleagues and co-workers who need to be aware of the symptoms and signs of difficulty. Heat stroke can be deadly and needs immediate medical attention. It is much less common than heat exhaustion and occurs when a person is no longer able to cool themselves and their temperature becomes dangerously high. The symptoms will be the same as for heat exhaustion but if left untreated people can develop:

  • confusion;
  • disorientation;
  • seizures;
  • loss of consciousness.

Coping with the heat

Employers have a duty of care to all workers, and can take a number of steps to help them cope with the heat and ensure they do not suffer the negative effects of ‘good’ weather.

In addition to an employer’s legal requirements to protect workers, regulating the temperature of the work environment has also been shown to be important in maintaining productivity. Research has shown that temperature generally impacts work performance.

  • Monitoring thermal comfort: There is no law or official guidance governing the maximum temperature in the workplace, but the law demands that workplaces are well ventilated and not subject to extreme temperatures. The Health and Safety Executive suggests that if more than 10% of staff in an air conditioned office (or 15% in a naturally ventilated office) complain about being too hot, a thermal comfort risk assessment should be carried out.
  • Introducing physical intervention to regulate temperature: Introducing air conditioning or fans into the workplace, creating barriers between the heat source and workers, or reducing the physical effort required by workers.
  • Regulating exposure to extreme temperature: Reducing the time spent in hot environments or near the heat source.
  • Encouraging workers to stay hydrated: Making sure that employees take on enough fluids during the day by offering easy access to water.
  • Training staff: Informing workers so they are aware of the impact of heat on their work and the symptoms of heat stress, heat exhaustion and heat stroke. Helping them to understand how to combat the effects of heat, and how to recognise when heat is taking its toll on them or others.
  • Acclimatisation: Allowing time for workers to adjust to hot conditions by restricting the time they spend exposed to extreme temperatures.
  • Monitoring the health of workers at risk: Being aware of the health needs of people with diabetes, lung or heart disease and reducing their exposure to extreme heat.

Reducing the risk of skin cancer

People who work outside (for example construction workers, farmers, sports people and postal workers) are particularly vulnerable to skin cancer, especially during the sunnier months. In the past 10 years skin cancer rates have increased by 56% for men and 36% for women, according to Cancer Research UK.

Employers can help employees by encouraging these steps:

  • Using plenty of high factor sunscreen (minimum of factor 15).
  • Applying sunscreen on all areas of skin, including ears, neck and bald spots.
  • Wearing sunglasses and broad brimmed hats.
  • Encouraging particular care among people with fair skin, freckles and moles.