Keep your cool about heat stress

As it becomes increasingly apparent that global warming is on the increase, growing numbers of companies, industries and governments are paying more serious attention to the problem of heat stress. HSM asks James Russell, managing director at Techniche Europe what measures can be taken to address this?

Heat stress is by no means only a problem of the future; it is a problem that health and safety professionals throughout the world already face today. Workplaces in the United States and Australia have been quickest to act, but we’re increasingly seeing companies in Europe taking steps to reduce the risk of heat stress among their staff.

So what is heat stress and why is it a problem? Heat stress occurs when the body stops being able to control its internal temperature. Under normal circumstances our bodies do this quite effectively – increasing blood flow to the skin’s surface and producing sweat, which evaporates from the skin’s surface and helps heat to escape.

However, if the body’s attempts to do this are hampered – as in environments where heat exposure is unavoidable or where protective equipment stops sweat from evaporating – then heat stress can be the result, putting the body under strain and resulting in heat-related illness. Symptoms of heat stress differ according to severity, but can include impaired concentration, fatigue, muscle cramps, heat rashes, severe thirst, dizziness, nausea, headaches, heavy sweating and clammy skin. The severest form of heat-related illness – heat stroke – can lead to confusion, convulsions, loss of consciousness and even death.

Naturally, some workplaces, such as those where the process itself produces heat, are at greater risk than others. However, the risk of heat stress in outdoor work environments such as those in agriculture and construction is definitely worsening as the world gets hotter.

In these types of workplaces, exposure to direct sun with no shade can substantially increase how hot the body gets. Higher air temperatures and humidity levels, as well as low air movement or strong winds with hot, dry air can also exacerbate heat problems. Sunlight reflecting off water, the ground and artificial surfaces can produce radiant heat, further compounding the problem. When combined with low fluid consumption, physical exertion or the use of bulky protective clothing and equipment, working in hot conditions outdoors can become extremely hazardous.

The good news is that when temperatures rise, there are a number of steps that employers can take to protect employees from heat stress.

These include:

• Education: Provide training for workers and their managers to make them aware of the heat stress risks associated with their work, symptoms to look out for and how to respond, as well as the importance of staying hydrated and taking rest periods in shaded or cooler areas
• Preventing dehydration: Provide cool water in the workplace and encourage workers to drink small amounts frequently before, during and after working
• Providing shade: In hot weather, shaded areas can have a much cooler ambient temperature than those in direct sun, allowing the body to get rid of heat more easily. Provide shaded rest areas and, if possible, consider moving work into shaded areas
• Providing protective clothing: Light coloured clothing reflects the heat and wide-brimmed hats provide sun protection, but specialised cooling clothing can actually help the body to keep cool, particularly when protective equipment has to be worn. For example, the Techniche HyperKewl™ crown cooler and neck shade attaches to the inside of a hard hat and uses evaporative technology to keep the wearer’s head and neck cool – between 6°C and 12°C cooler than the ambient temperature – for several hours while also protecting them from the sun
• Allowing workers to acclimatise: Gradually increasing workloads and exposure while taking frequent breaks for water and to rest in a shady or cool area can enable the body to build up some tolerance to working in the heat. Allow new workers and those returning from absence to acclimatise to reduce their heat stress risk. In addition, during a heat wave, even experienced workers may need to acclimatise to the higher temperature
• Scheduling work to reduce sun exposure: Schedule the hardest physical tasks for the coolest parts of the day, rotate workers to reduce their heat exposure and move work away from direct sun or radiant heat sources.