Staying Cool: How to Avoid Heat-Related Illnesses in the Summer

By William Atkinson | May 15, 2019
Staying Cool Heat-Related Illnesses




According to the National Weather Service, the 30-year average for weather-related fatalities from 1988–2017 puts heat as the most frequent with 134 deaths per year, followed by flood at 85 per year and tornado at 69 per year. Lightning, which gets a lot of coverage, comes in seventh with 44 deaths per year. Rounding out the bottom two spots are winter at 40 deaths per year and cold at 30 deaths per year.

This data includes all people in the United States and it is important to remember, during excessive heat, many people can seek shelter in cooler, shaded or indoor areas. But employees working outside do not always have that option. By the nature of their jobs, they are in the heat and often directly in the blazing sun.

A report published by the National Institute for Occupational Safety and Health (NIOSH), “Workplace Solutions: Preventing Heat-Related Illness or Death of Outdoor Workers,” notes that, between 1992 and 2006, 423 workers died as a result of exposure to environmental heat. A 2018 study, “Assessing Heat Stress and Health Among Construction Workers in a Changing Climate: A Review,” published in the International Journal of Environmental Research and Public Health, notes that, “Previous studies have shown that construction workers in the U.S. are 13 times more likely to die from a heat-related illness compared to workers in other industries.”

While workers are exposed to more direct sunlight in wide, expansive, outdoor areas, heat also is a problem in confined areas, such as cities. A Science News article notes, “Heat thrives in cities. All of the nonreflective roofs, walls, roads and other surfaces absorb and retain heat during the day. Waste heat, emitted from air conditioners and vehicles, concentrates in cities, too.” These factors combine to create an “urban heat island,” an amplification of heat that occurs within cities.

Adding to the challenge, the average worldwide temperature has been the highest ever recorded over the past four years, and nine of the 10 hottest years have been this century (with the tenth being 1998).

In addition, workers with certain medical conditions are even more susceptible to heat-related illnesses. According to a 2018 study, “Evaluation of Occupational Exposure Limits for Heat Stress in Outdoor Workers—United States, 2011–2016,” published by the Centers for Disease Control and Prevention (CDC), personal risk factors include obesity, diabetes, hypertension, cardiac disease, and use of certain medications and illicit drugs.

According to NIOSH’s report, outdoor workers are exposed to two forms of heat stress: internal metabolic (body) heat generated by exertion (hard physical labor) and environmental heat arising from working conditions.

“Moderate to high air temperature, particularly with high humidity; direct sun exposure; heavy or vapor-barrier clothing; and lack of adequate water, rest periods, or cooling-off conditions all contribute to environmental heat stress and can make exertional heat stress worse,” the report states. “Workers of all ages are susceptible to heat-related illness, and their symptoms may quickly become worse after exposure.”

NIOSH further explains that the human body tries to reduce the strain from excessive heat by sweating and increasing blood flow to the skin to promote cooling.

“Heat-related illnesses occur when heat exposure or physical exertion increases to the point at which the body’s attempts to cool itself are no longer effective,” the report states.

According to NIOSH, there are six types of heat-related illnesses, which it lists in order from most to least serious: heat stroke, heat exhaustion, rhabdomyolysis, heat syncope, heat cramps and heat rash. For details and first aid measures that should be taken for each, as well as recommendations for training, infographics and resources, visit


The CDC study suggests a number of strategies to reduce worker exposure to heat-related illnesses. These include an acclimatization schedule for newly hired workers and unacclimatized long-term workers (e.g., during early-season heat waves); training for workers and supervisors about symptom recognition and first aid; engineering and administrative controls to reduce heat stress; medical surveillance; and provisions for fluid and shady areas for rest breaks.

NIOSH offers more specific recommendations:

  • Limit worker time in heat and/or increase recovery time spent in a cool environment.
  • Use special tools intended to minimize manual strain.
  • Train supervisors and workers about heat-related illnesses.
  • Implement a buddy system in which workers monitor each other for signs of heat intolerance.
  • Provide adequate amounts of cool, potable water near the work area, and encourage workers to drink frequently.
  • Implement a heat-alert program whenever the weather service forecasts a heat wave is likely to occur.
  • Institute a heat-acclimatization plan, and increase physical fitness.

NIOSH further breaks these down into four subcategories: training, acclimatization, hydration and rest breaks, each with several specific recommendations, which are available on the CDC website as text and infographics.

NIOSH also recommends employers introduce a medical monitoring program, which is intended to prevent adverse outcomes and identify early signs and symptoms associated with health-related illness. According to the report, “Employers should provide medical evaluations and procedures performed by or under the direction of the responsible healthcare provider, including preplacement and periodic medical evaluations, as well as a plan for monitoring workers.”

NIOSH says training should include information about heat stress, risk factors, signs and symptoms and first aid: “Proper precautions (e.g., hydration, rest breaks, acclimatization, etc.) for work in hot areas should be explained. Workers should also be trained on the effects of therapeutic drugs, over-the-counter medications, alcohol, and caffeine, which may reduce heat tolerance and increase the risk of illness. Proper care and use of heat-protective clothing and equipment should be explained and demonstrated. In addition, supervisors should be trained on monitoring weather reports and responding to hot weather advisories.”

Beyond engineering and administrative controls and measures, employers should consider safety equipment and clothing specifically designed to reduce worker exposure to heat-related illnesses.

The International Safety Equipment Association (ISEA) promotes this strategy on its website: “ISEA urges outdoor workers to stay hydrated and drink plenty of fluids such as water or electrolyte-replacing beverages. Hydration helps to prevent dehydration, which is the primary cause of both heat cramps and heat exhaustion. Taking breaks and cool down periods, as well as wearing heat stress protection safety equipment, will help reduce heat-related illnesses.”

In specific, the ISEAit recommends the following:

  • Use cooling vests and other cooling clothing or accessories to help keep overall body temperature at a moderate level.
  • Wear broad-brimmed hats and lightweight clothing to reduce direct sun exposure.
  • Wear lightweight, sweat-wicking, fast-drying clothes. Sweat causes the body to work even harder to stay cool as it adds an insulating layer to the skin.

ISEA members that offer heat stress-related products provide a wide range of options. These include cooling vests, protective clothing, heat-resistant gloves, respiratory cool tubes, neck shades, hard hat sun shades and brow pads, sweatbands, cooling towels, water bottles, hydration packs and electrolyte tablets.

On-the-ground solutions

Commonwealth Electric has a comprehensive safety program to protect workers from heat-related illnesses. The contractor has six locations in Nebraska, one in Iowa and two in Arizona, including one in Phoenix, which holds the record for the most average number of days per year (107) with temperatures above 99 degrees.

“We focus on OSHA’s mandate of ‘water, rest and shade,’” said Ruben Bera, the company’s corporate safety director.

The company considers water hydration to be the most important element of its heat safety program. To encourage this, the company educates its people that dehydration can start up to two days prior to them feeling dehydrated.

“This is why we encourage them to stay hydrated over the weekend, so they can show up to work Monday mornings fully hydrated,” he said.

At all of the company’s locations, supervisors encourage employees to take breaks in shaded areas. While employees can also go inside to access air conditioning, the company doesn’t recommend a lot of that, because transitioning between the heat and the cold may cause respiratory infections.

The company’s other recommendations are unique to the work location.

“When it comes to clothing, most of our guys in Arizona prefer to wear long-sleeve shirts, which they say keep them cooler and protect them better from the sun,” Bera said. “We also allow them to wear the extended brims on their hardhats, which provides them more shade.”

When the weather forecast predicts extremely hot temperatures, the company alters its work hours, often starting at 4:30 or 5:00 in the morning, while it is still dark, and then stopping work earlier in the day.

“In the Midwest, we get heat, but also humidity,” Bera said. “As a result, we encourage our guys to wear loose clothing. The last thing you want is excess clothing that ends up holding a lot of sweat. We also provide them with liners and sweatbands to wear inside their hardhats, if they request them.”

Two Las Vegas contractors have innovative and efficient ways to keep their workers hydrated.

“Years ago, we paid a service to bring out 5- or 10-gallon jugs to work sites,” said Kenny Whipple, Sturgeon Electric district manager. “However, nine out of ten times, because of where they were dropped off, they would be stolen before we arrived.”

If they weren’t stolen, crews would have to haul the heavy jugs around, which was inconvenient.

“Another problem was that we had to deal with 4-ounce cone paper cups,” he said.

On smaller jobs, the company arranged to have ice chests on-site filled with bottled water.

“However, we ended up having guys making $75 an hour having to stop to buy ice every day,” he said.

Now Sturgeon has purchased 15 or 20 small, used refrigerators.

“Since we are the ones who manage temp power on our jobs, we make sure we have power for these fridges, which we stock with bottled water,” Whipple said. Now, everyone has quick and easy access to cold water on the job.

Starting in 2018, Mojave Electric replaced its Igloo water coolers and cups with hydration stations: modified Knaack tool boxes, filled with single-use water bottles. Each station has a refrigerator and venting, with an external power cord, and holds about 22 cases of water.

The water is exchanged one for one. That is, each time a worker takes out a cold one, he or she replaces it with a warm one.

“One hydration station is assigned to each crew and located in the work area, readily accessible to all workers on the job,” said Dave Warnock, Mojave safety supervisor.

Take a cue from these ECs to keep workers safe this summer.

About The Author

ATKINSON has been a full-time business magazine writer since 1976. Contact him at [email protected]





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