Nice weather has finally arrived and many workers are feeling the heat. It is now the season to expect heat-related illnesses in the workplace. Summer may put many workers at risk of heat stress and seriously injure them. A series of hot and humid days following one another may adversely affect workers who did not previously acclimatize to heat exposure. Extreme heat directly affects the health of workers, puts their safety at risk with impaired judgment and reduces productivity. This is a significant issue not only for occupational health and safety of people but also for the effectiveness of an organization as a whole. While Heat Stress Prevention Plans are complex and their development is better left to the professionals, every responsible supervisor should know some key facts to manage work in extreme heat on a daily basis.
Did you know?
Loss of consciousness because of heat stroke is classified as a critical injury and is a reportable event under the Occupational Health and Safety Act.
Who is most susceptible to heat stress?
Fortune examined the sectors with the highest risk of heat stress and found that the sectors highest on the list were those with a lot of outdoor work. The top three are workers in government services, agriculture, followed by construction and business service. Government services included workers who maintained parks, fought forest fires and collected trash. Other professions who are inclined to suffer seasonally from this hazard include military personnel, landscapers and hazardous materials abatement contractors. Employers should also look out for new workers on the job. New unacclimatized employees working in manual occupations and ‘young workers’ who may not realize the risks are most vulnerable to extreme heat.
There is a range of heat illnesses and they can affect anyone, regardless of age or physical condition.
What contributes to heat-related illness and how to mitigate the hazard?
Environmental factors such as high temperature, high humidity, and radiant heat sources such as direct sunlight, ovens, boilers, steam pipes and engines can contribute to heat stress. The best way to remedy this is to make the work environment cooler through engineering control measures such as convection, radiant or evaporative heat control measures.
Did you know?
Just 30 minutes of exposure at the temperature of 40 C is enough to cause permanent disability or brain damage.
Administrative controls such as limiting exposure times or temperature, reducing metabolic heat load, enhancing tolerance to heat, screening for heat intolerance, health and safety training and instituting a heat alert or hot weather program are suggested. Equally important are ensuring personal hydration, acclimatization of employees, controlling work duration times and monitoring the levels of physical exertion as key components of combatting heat-related illnesses. It is considered the next best method to protect workers because it allows employers to proceed with work without eliminating the source of the danger.
Conjointly with administrative controls, Personal Protective Equipment must be reviewed. PPE and protective clothing is the third level of protection from heat stress. Selecting the proper PPE for each situation can dramatically lower the effects of heat – and it is not the only reason to review all PPE use. In hot conditions, PPE that protects workers from other hazards may become uncomfortable and workers may then avoid wearing it. This is an issue that consultants frequently encounter when conducting inspections on job sites. For example, abatement contractors working in enclosures may avoid wearing a full-face air-purifying respirator in hot conditions where a powered air-purifying respirator that provides airflow across the face will be more comfortable. The impermeable clothing required for abatement work prevents heat exchange from the body to the environment and contributes to heat burden. Auxiliary body cooling may be required in the form of water-cooled or air-cooled garments or cooling vests.
There is no standard set of measures to prevent heat-related illnesses, so the best solution to comply with regulations and keep workers safe is to establish a Heat Stress Prevention Plan unique to each project or workplace (Ask THEM for assistance). Many physical factors affect the solutions that will be implemented: the age of workers, their state of health and physical fitness, required work tasks and personal protective equipment, as well as available resources – all play a role in finding the right solution. While each situation is unique, all plans share these common elements:
- Methods to monitor temperature and humidity levels.
- Description of conditions when heat stress measures should be implemented.
- Outline of engineering controls and administrative controls.
- Outline of proper PPE/clothing.
- Emergency response measures.
- Training requirements for all workers and supervisors that include the signs, symptoms and prevention of heat stress and how to deal with those risks.
Heat Stress in Indoor Environments
Although heat stress is typically associated with seasonal outdoor work environments, heat can be a year-round hazard in indoor workplaces. Commercial bakeries, kitchens, laundries and environmental abatement sites are just some activities that may be affected. In these workplaces, workers are often near sources of radiant heat or inside buildings with limited cooling capabilities and air movement.
Should an individual in an indoor work setting use the same preventive measures for heat stress as someone working in an outdoor setting?
Measures to prevent heat-related illness are similar in both indoor and outdoor environments, but indoor workplaces have additional concerns. For example, an indoor environment with little airflow may diminish the cooling effects of that sweat provides through evaporation. Nonetheless, these environments also provide additional opportunities to use engineering control measures. As with outdoor work environments, it is important to develop a prevention plan to handle the potentially hazardous indoor heat.
T. Harris Environmental Management Inc. is experienced in assessing workplace factors that may contribute to heat stress/heat strain are able to provide recommendations on engineering and administrative controls. We can help conduct a detailed analysis of work areas regarding clothing properties, worker demands, task times and thermal environment according to the ACGIH threshold limit value as recommended by the Ontario Ministry of Labour. We can help you determine if excessive heat strain is occurring and whether general controls or job-specific heat stress/heat strain controls are required in your workplace. Please call us to conduct an assessment.