As a widely preventable cause of death, why are we still tackling heat stroke? Alwyn Mendonca looks at the key hazards at play and offers life-saving, simple solutions.
Occupational deaths from heatstroke differ from those in the general populous. Intense physical exertion combined with insufficient hydration, inadequate rest, and ‘protective’ clothing that fails to let heat escape from the body all catalyse the difficulties and dangers of hot environments. Even without these added obstacles, merely existing in the heat is too much stress on some individuals. Those at higher risk of heat stress include: the elderly, people with existing physical/mental health conditions or on certain medications, pregnant women, children, and – last but not least – those working in the heat.
“when your workers are exposed to high temperatures, everyone needs to be aware of the dangers of the heat”
We have all heard that during the summer months, exposing workers to extremes of heat results in widespread heat illnesses. The workers who are most exposed to heat illnesses are labourers working outdoors, such as construction workers, cleaners, and agricultural workers to name but a few. The ill health these workers face includes minor conditions such as heat cramps, heat syncope, and heat exhaustion, as well as the more severe condition known as heat stroke, which may lead to death.
In addition, excessive heat causes accidents at workplaces in many other ways. It becomes more difficult to concentrate on the job due to rigorous sweating, leading to workers becoming increasingly tired and nervous. With all these factors, so too creeps in an increased level of errors in judgment. In extreme situations, a lack of consciousness may occur due to severe dehydration.
It stands to reason, therefore, that when your workers are exposed to high temperatures, everyone needs to be aware of the dangers of the heat.
Statistics from the National Safety Council show that, since 1936, there have been 30,000 deaths caused by heat related illnesses. On average, 384 people die each year from heat stroke. Heat related injuries seem to mostly affect the aged workers, people who are not in good physical and mental health, pregnant workers, and those not acclimatised to the heat.
Healthy human ‘core’ or deep body temperature is maintained within a narrow range of 37°C ±1.5°C. The body is incredibly well designed, with many mechanisms in place to self regulate its core temperature against fluctuations encountered every single day. To prevent it from increasing when exposed to heat, the body sweats and increases blood flow to the skin. When muscles are being used for physical work, most of the blood is flowing to muscles and less blood is available to flow to the skin and release heat. If the body can’t dispose of excess heat, it will store it. When this happen the body’s core temperature of 37°C rises and the heart rate increases. Generally, when body temperature reaches above 40°C, the thermo-regulation mechanism of the body fails.
“the body’s temperature increasing to 40°C is a severe medical emergency which could result in death”
Heat stress is known as the body’s reaction to overheating when it cannot cool by itself through sweating due to dehydration, or in other words, loss of body fluids/water lost due to sweating which are then not replenished through drinking more water. It is of paramount importance to drink water regularly when working in hot environments even though you are not feeling thirsty. Employees should remember that they can deplete as much as 30% of their body’s water when working in the heat before they even begin to feel thirsty.
Heat related illness and symptoms
The reactions shown by the body during excessive heat exposures may vary from mild to severe, as explained in the following sections. These include: heat rash, heat cramps, heat exhaustion, heat stroke, and heat syncope.
This condition, also known as prickly heat, occurs when exposed to hot and humid environments where sweat can't easily evaporate from the skin. Due to this rashes are produced, which in some cases cause severe pain.
Heat rashes can be prevented or at least minimised by resting frequently in cool places and bathing regularly, ensuring to thoroughly dry the skin. Do not scratch skin rashes, but do apply anti-itch lotion. Wear loose-fitting cotton clothes that dry away the sweat.
Due to the loss of body salts and electrolytes, excessive sweating can result in painful muscle spasms that will usually affect the stomach, arms and legs. Providing workers with fluids containing electrolytes such as calcium, sodium and potassium may help in minimising the risk of heat cramps.
This is a condition created by the loss of fluids lost during excessive sweating. Individuals with heat exhaustion still sweat, but they experience extreme weakness and may even collapse. They may experience nausea and headache. The signs include clammy and moist skin; pale complexion, thirst, and dry mouth. Heat exhaustion usually occurs when the body temperature reaches around 39°C.
This condition is best treated by immediately taking the patient to a cool place, applying cool compresses, elevating the feet, and giving the individual plenty of fluids with electrolytes. More severe cases may require immediate medical treatment and probably transfer to hospital.
Heat stroke occurs when the body’s core temperature gets too high and the body is no longer able to cool itself. This generally results when the body’s temperature increases to 40°C. This is a severe medical emergency which could result in death.
An individual suffering from heat stroke will have hot and dry skin – by this point the body’s temperature regulation mechanism of sweating has failed – their pulse will be high and their blood pressure will fall. They will have an extremely high fever, as well as mental and neurological disturbances.
Heat stroke is a fatal condition and must be treated by immediately cooling the victim's body with water spray or wrapping them in wet sheets. Immediately seek medical attention by calling an ambulance.
Do not use ice or very cold water for cooling as it can result in superficial narrowing of the blood vessels, which can prevent loss of heat from the skin surface.
The condition of heat syncope usually occurs in individuals standing erect and immobile in the heat for prolonged hours, as this can reduce the effectiveness of blood circulation. A knock on consequence of poor circulation is that brain cells get affected when oxygen does not reach them; however, the person recovers rapidly after lying down.
Other ill health conditions
There may be specific ill health effects in certain individuals who have existing cardiovascular conditions or heart diseases. Their heart may be compromised or fail to work due to the excessive heat exposure. Heat edema is another possible condition workers may face in which dilation of blood vessels (from the heat) enables body fluid to gravitate into the arms and hands, resulting in swollen feet, ankles, legs, hands and wrists.
Contributory factors to edema include:
- A diet high in salt • Being overweight
- Staying in the same position for a prolonged period
- Certain medicines
- Being pregnant
- Injuries, such as sprains or strains
Preventing heat illness
This process involves acclimatising an individual to the heat prior to long durations of physical activity. The body settles to the excessive heat when progressively acclimatised day by day under controlled conditions. In the Middle East many workers originate from geographically diverse locations, meaning some may be more adapted to the heat, while others coming from colder climates will struggle more. It is particularly important for these people to gain a familiarity with the hot climate, to prepare the body for working in those conditions.
Maintain body fluids
Workers must be provided with sufficient drinking water throughout the course of physical activity and should be encouraged to drink regularly. Do not rely on thirst as an indicator of dehydration because your body loses water faster than you realise. As the saying goes: “Once you’re thirsty, it’s too late!” If you do drink it, alcohol should be avoided because it increases dehydration and can interfere with heat loss – as do caffeinated and sugary beverages.
Eat small light meals and stay away from heavy foods for the best chances of coping well with the heat. Dense and filling dinners can increase metabolic heat production, increasing water loss. To avoid this, eat smaller, well-balanced meals more often.
Take frequent rest periods in a shaded area and drink plenty of fluids in between the physical work activity. Pace the work activities at a slower rate during high temperatures.
Lightweight and light-coloured clothing reflects heat and sunlight, helping the body to maintain normal temperatures.
Wear loose-fitting clothes such as cotton which lets air move over the body. Wide brimmed hats also provide protection by giving shade to the head.
Information, instruction, training and supervision
Employee awareness is an essential part of minimising the risks of ill-health from the heat. Information regarding the same can be provided through posters, playing cards or handouts, such as displaying – while it may sound bizarre – urine charts to teach workers about dehydration by checking their urine colour. Instructions regarding the control actions to be taken by workers should be explained through regular toolbox talks and trainings.
Providing supervision during work is highly essential to identify any ill health conditions and call for help.
First aid arrangements
Organisations must be equipped with first aid facilities as well as with qualified first aid persons who will competently know what action to take when heat illnesses occur, and be able to recognise the signs and administer care promptly. First aiders must be well versed with CPR and other first aid techniques to face the worst-case scenarios, such as heat stroke, that may result in patients not breathing, unresponsiveness, and other life threatening conditions that need first aid either to prevent the condition escalating to the point that emergency services are needed, or to give medical attention while waiting for emergency services to arrive. Emergency numbers must be displayed in prominent locations so that workers can get in contact with the emergency services at all times.
Countries like the United Arab Emirates and other Middle East countries are prime locations where generally temperatures soar to extremes in the summer months, making outdoor work during the day virtually impossible. It goes without saying that because of this workers in such places are more prone to heat related illnesses than in other, cooler parts of the world. The local governments have taken precautionary steps with regards to protecting workers from heat exposures during peak summer hours. For example, Abu Dhabi Occupational Safety and Health centre (OSHAD) has launched the Safety in Heat programme to raise awareness about the procedures that must be implemented for the heat stress management programme by employers and supervisors in order to protect workers from the summer heat in the Emirate of Abu Dhabi. The Safety in Heat programme is supported by the United Arab Emirates (UAE) Ministry of Labour in accordance with the law that states employers must not allow workers to perform any outdoor activities from 12:30pm until 3:00pm. This law is applied for three months from June 15 to September 15 every year. A huge number of the workforce has been benefited from the initiative, but employers do not always comply.
“crucial to the safety of workers in hot environs is providing heat stress training to workers”
Excessive heat exposure can prove fatal, so whether you’re responsible for workers in the heat or it’s you going out into the furnace of summer work for another uncomfortable day of sweating, it’s not a matter to take lightly.
There are many other general precautions that can be taken by employers during the summer months to safeguard workers. Maintenance and repair contracts that would be carried out in hot environments can be scheduled for cooler months, or at the least planning jobs that are most physically demanding for the cooler part of the day. The pressure can be further lessened by providing workers with mechanical aids to reduce the job’s physical demands. Alternatively, relief employees or extra employees can be assigned for physically demanding jobs such as lifting and manual handling. All the while, employees who are at risk of heat stress, especially aged workers, should be monitored.
Being acclimatised to heat helps a great deal, so exposing employees to hot workplaces for progressively longer periods then enables them to work for longer. That said, frequent rest periods are essential in lasting out working in hot weather. Cool areas should be provided – ideally with either air conditioning, fans, or both. During these rests, you should also provide cool water or liquids to employees such as oral rehydration drinks (ORS). At the same time, it’s important that workers are aware to avoid drinks with caffeine, alcohol, or large amounts of sugar. While these may temporarily quench the thirst, they actually dehydrate you.
Crucial to the safety of workers in hot environs is providing heat stress training to workers. It should include information about identifying heat hazards, prevention methods, symptoms of heat illnesses, the importance of monitoring oneself and co-workers for symptoms, treatment, and PPE.
With hydration, regular breaks, correct PPE, keeping in mind some basic heat stress training, and a common sense attitude, you and your colleagues will get through another summer and head home safe.