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Heat stress: preventable, but common and costly

While many employers are proactive and do an excellent job training workers to prevent heat-related injuries, every year thousands of workers become sick from occupational heat exposure, and some even die. It can happen to anyone and it can happen anywhere. Some of the fatalities in 2013 included: an employee working on a conveyor line in Brooklyn, NY, a landscaper in Hartland, WI, a worker involved in bulldozer and pick up truck operations in Reinholds, PA, a letter carrier in Medford, MA, a newly rehired employee working for an electrical contractor in Chicago, Il, a truck driver in Golden Meadows, LA, a temporary garbage collector in Houston, TX and a farm worker in Five Points, CA.

Heat related exposure includes not only heat cramps, heat rash, heat exhaustion, fainting and heat stroke, but also injuries from falls, equipment operation and accidents that occur when a worker has sweaty palms or fogged safety glasses or becomes dizzy, disoriented, or fatigued as a result of dehydration. While there are year-round indoor jobs such as laundries, bakeries, factories and so on that can lead to heat-related risks, seasonal outdoor work during the 'dog days' of summer leads to a spike in injuries and deaths.

Here are five points that will help employers prevent heat related injuries and illness:

  1. Everyone reacts to heat differently

    Some workers are more susceptible to heat than others. According to NIOSH, while workers can acclimatize themselves to different levels of heat, each worker has an upper limit for heat stress beyond which that worker can become a heat casualty. This varies by body size, state of wellness, lifestyle, etc.

    Workers who are at higher risk include:

    • Workers who have pre-existing medical conditions. Workers taking medication for high blood pressure or taking anti-depressants have been found to be more susceptible to heat because certain medications can inhibit the body's ability to regulate its temperature.
    • Workers who are overweight
    • Pregnant workers
    • Workers who use drugs and alcohol
    • Workers who have had a heat-related illness in the past
    • Workers who wear personal protective equipment (PPE)
  2. Acclimation periods should vary by experience of worker and working conditions

    To ensure workers are fully acclimatized to heat, OSHA suggests employers begin with 50 percent of the normal workload and time spent in the hot environment, gradually building up exposure and workload to 100 percent by the fifth day. However, OSHA cautions that workers performing strenuous activity, workers using heavy or non-breathable protective clothing, and workers who are new to an outdoor job need additional precautions. When Cal/OSHA investigated 25 incidents of heat related illness, in almost 50% of the cases the worker involved was on their first day of work and in 80% of the cases the worker involved had only been on the job for four or fewer days. Acclimation to hot weather is a big factor as it can take up to two weeks for a person new to outdoor work to get used to the temperature and even more for those who are overweight or have other at risk factors.

  3. Change behavior when heat index rises

    All workers are at greater risk of suffering a heat related injury or illness when there is a heat wave. While this may seem like a "duh" statement, often the biggest challenge in preventing heat-related illness is making sure workers change their behavior and that policies are followed at the worksite when the heat index rises.

    During heat waves air temperatures rise above normal quickly, and even experienced workers will not be able to immediately acclimatize to the new, hotter temperatures. They may minimize the early warnings of heat exhaustion, such as irritability, thirst, headache and heavy sweating, rationalizing that these as "normal" in hot environments. Workers will need more breaks and rescheduling some of the harder and hotter job tasks may be warranted.

    OSHA has a helpful app to measure the index and receive tips on protective measures and a fact sheet on how to use the heat index.

  4. Understand hydration

    Studies show that dehydration levels of 2% of body weight or more impair visual motor tracking, short-term memory, attention and arithmetic efficiency. Moreover a 23% reduction in reaction time occurs at the 4% dehydration level. Such declines in cognitive performance can significantly increase the risk of work-related accidents.

    While having plenty of water in convenient locations close to the work site is essential, workers should be educated on the importance of proper hydration. It is a common misconception that taking fluids to hydrate the body is enough to prevent heat stress; however, in certain circumstances it can take as much as 24-hours for the body to absorb enough fluid to fully rehydrate. Employees need to recognize the importance of monitoring off-the-job behavior.

    On the job, workers should be reminded to drink water frequently before becoming thirsty in order to maintain good hydration. In addition to providing plenty of water, NIOSH encourages employers to provide urine color charts near toilet facilities. These charts show the urine colors of a hydrated person compared to a dehydrated person. The darker the urine, the more likely your body is dehydrated.

  5. Have a plan

    The best defense against heat-related illnesses is prevention. The good news is that resources are plentiful and costs minimal. Training employees about heat stress, how it affects their health and safety, the warning signs and how it can be prevented is key. While there are no national OSHA regulations and only a few states such as California and Washington have heat illness prevention standards, OSHA has a heat illness prevention campaign that offers extensive educational materials. As in all job training, language, reading proficiency and cultural barriers need to be taken into account.