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3 Steps to Prevent Heat-Related Illnesses

A flaming thermometer next to the words Beat the Heat mobile view

Preventing heat-related illnesses at job sites has no easy answers or standard prescriptions, says EMC Senior Industrial Hygienist Dave Havick. That’s because there are many variables to manage, and best practices are different from company to company, project to project, and even employee to employee. “That is reality, and it all comes down to knowing your situation and your employees well enough to make the right calls at the right time,” he says.

If you are in construction, landscaping or other industries with outdoor workers, you know your workers are at risk when it’s hot outside. But sometimes forgotten are indoor workers in foundries, near ovens and in factories or warehouses without air conditioning.

Start With the Heat Index

Temperature plays a huge role in heat-related illnesses. So does relative humidity, which amplifies the effects of heat because sweat isn’t evaporated as effectively when there’s a lot of moisture in the air.

Calculating the heat index is a starting point for preventing heat-related illnesses. This index, a combination of heat and relative humidity, gives a baseline for danger in the outdoor work environment. There are various ways to calculate this, including OSHA’s Heat Safety Tool. Indoors, an inexpensive temperature and humidity gauge can provide similar numbers, which can be plugged into the app. You can also input the air temperature plus either the dew point or relative humidity into a calculator found on the National Oceanic and Atmospheric Administration website.

Use the heat index to plot your next steps. OSHA provides a risk-level chart that includes a list of actions, including alerts, rest breaks and recommended water intake.

Also Account for These Variables

While the heat index is a good guide, it doesn’t handle every situation. Other variables are trickier to pin down as they are situation dependent. You’ll have to factor in the individual challenges your workers face as you fine-tune your responses to heat and humidity. Some of the variables to consider include:

  • Air Movement―Moving air evaporates sweat, allowing bodies to stay cooler. For outdoor workers, this is usually wind, while fans may serve this purpose indoors. You can’t increase the wind, but you may be able to add some outdoor fans to improve air circulation. Indoors, make sure that the fans are positioned to reach all workers. However, keep in mind that at very high temperatures, air movement can actually increase heat stress.
  • Sun vs. Shade―Working in bright sunlight can boost the temp about 15 degrees, so those workers in the sun need extra TLC. Shade is important for resting times if there are no air-conditioned spaces available, although it will take longer to cool down outdoors in the shade.
  • Activity Level―If your employees’ jobs include high levels of exertion such as stacking items, shoveling gravel or lugging heavy timbers, the dangers of heat stress are increased.
  • Required Clothing―Welding gear, chemical protective suits and other personal protective equipment burdens workers with extra layers. If heat can’t escape and air can’t penetrate, the gear acts like a sweatbox. Workers wearing these items need other ways to cool down.
  • Physical Conditioning―Employees who are used to the weather, gear and heavy activity can handle more heat than new employees who aren’t accustomed to the routine. In one OSHA report, nearly 80% of heat-related illnesses involved workers who had been on the job for 4 or fewer days. Newbies also may be reluctant to let anyone know they are suffering.

3 Steps That Work in Most Situations

Some solutions work in most situations to prevent heat-related illnesses. You’ll still need to finesse the timing of breaks and amount of fluids, but you can prevent problems if you err on the side of caution.

  1. Encourage fluids.

    Workers in extreme conditions need to drink more water than they may realize. Encourage them to drink at will while working―in addition to during breaks―because gulping water during a 15-minute break and then working for 45 minutes won’t necessarily prevent dehydration. The amount of water needed will vary by conditions, but for moderate activity, the National Institute for Occupational Safety and Health (NIOSH) recommends 1 cup every 15 to 20 minutes.
  2. Adjust break times as conditions get harsher.

    Taking breaks in the shade or under a canopy may be your only option, but understand that cooling down this way takes longer than if workers can rest in an air-conditioned breakroom. In extreme situations, accept that breaks may be longer than the amount of time spent working, or decide that conditions are too dangerous to continue working. You may have to reassign workers indoors or send them home.
  3. Check on everyone frequently.

    This especially applies to new workers or those not fully acclimated to the conditions, as well as older or heavier employees and those with medical conditions. Even young, healthy workers can get sick in extreme conditions, so keep an eye on everyone and have workers watch out for each other, too. Watch for symptoms of heat-related illnesses such as nausea, dizziness and extreme sweating, and intervene before the situation becomes dangerous.

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