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Extreme Heat Waves Pose Increasingly Deadly Risks To Construction Workers

Construction workers make up more than a third of heat-related deaths on job sites. As record-shattering heat waves spread to temperate cities, more construction companies are forced to grapple with how to protect their workers against the worsening climate, and failure to do so could have deadly consequences.

A construction worker was among those who died in the Pacific Northwest's "heat dome" event last week, when temperatures eclipsed 116 degrees. This week, New York City workers are laboring through the area’s third heat wave over the past month — all of this after 2020 was the second-hottest year in Earth's history, after 2016.


As the Earth gets hotter and heat waves in temperate areas become more common, the construction industry is adapting to grueling summers and coming up with ways to mitigate the risk now and in the future. 

Companies are increasing the number of fans used on sites, providing extra water, electrolyte-infused popsicles, educating their workers on the signs of illness, allowing for more frequent breaks and at times stopping work entirely for a couple of hours or a day, industry experts told Bisnow.

In days with a heat index over 100, “you can imagine what it's like working on a roof,” Eastbound Construction CEO Alex Elkin said. “If you're putting down a torch down roof, and you're operating a blowtorch and it's this hot out, you're really not going to be able to go very long before you need a break.”

Thousands of workers fall ill due to the heat each year, according to the Occupational Health and Safety Administration. Between 1992 and 2016, 285 construction workers died from the heat, accounting for 36% of these types of deaths across all professions despite making up just 6% of the workforce, according to the Center for Construction Research and Training, also known as CWPR. 

Climate change has propelled these extreme weather conditions, an overwhelming majority of climate scientists say; over the next 100 years, average temperatures on Earth are expected to rise between 2.5 and 10 degrees Fahrenheit, according to NASA. 

The global temperature has risen around 0.14 degrees Fahrenheit in recent decades, according to the National Oceanic and Atmospheric Administration. Worker deaths per year have increased 44.2%, from 9.5 per year between 1992 and 2002 to 13.7 per year between 2011 and 2016, the CWPR report showed.

The risk of illness and death from the heat is even higher when the change in temperature is sudden, like in the case of a heat wave, according to OSHA. Some 50% to 70% of deaths from heat happen within several days after the temperature change because workers don’t have time to acclimate, the administration said.

During the Pacific Northwest heat wave last week, British Columbia saw a 195% increase in sudden deaths, according to British Columbia’s chief coroner.

Skanska Environmental Health Safety Director Carlos Alvarez, who is based in Houston, said the most important advice he would give to construction companies in areas that typically don’t see intense heat is to get used to the heat slowly. 

“It's really important that they don't stay out in the heat all day long, exposing their bodies to such a drastic change in the environment,” he said. 

In order to successfully manage heat across areas that are typically very hot and those that are becoming increasingly hot, Skanska uses a plethora of tools and techniques, Alvarez said. 

Many have the Centers for Disease Control and Prevention’s OSHA-NIOSH heat safety tool app, which tracks the temperature, humidity and heat index based on GPS location. By connecting with NOAA, it can track the most up-to-date temperature and feel-like temperature, he said. They also have cooling stations in shaded areas, with large fans and water hoses nearby that mist the workers.

Skanska Environmental Health Safety Director Carlos Alvarez holds up the heat index app that Skanska uses to track the heat on work sites.

The stations also include ice buckets with water and electrolyte ice pops as well as hydration supplements that mix into water such as Working Athlete, Alvarez said.

“Not only is it important to drink water, but it's also to replace the electrolytes and the salts and the vitamins that you're losing throughout the hot day that also help with muscle recovery,” he said. 

Before vaccinations, when workers were required to wear masks, Alvarez said that around each hour the workers were mandated to take a 15-minute break at the cooling area to avoid heat-related illnesses. The CDC recommends required breaks, and without them, many workers try to push through heat.

“Sometimes somebody doesn't want to admit that the heat has overwhelmed them, so you have to protect them against themselves,” CNY Group Executive Vice President and Director of Field Operations Dennis Prude told Bisnow. “Construction is technical, but it's also psychological ... so you have to talk to a person and you tell that person, ‘Listen, most important is your family. You want to go home to your family healthy.’” 

Workers need to be taught signs, symptoms and prevention of heat related-illness, Associated General Contractors of America Director of Safety and Health Services Kevin Cannon said. During the recent heat wave in the Pacific Northwest, the Oregon chapter of the AGC sent out a safety plan to all of its members to help to educate them on the dangers of heat.

“Education is key,” he said. “Not only for the workers but also for your field supervision, training them on the signs and symptoms of heat exposure, heat illness." 

In the Northeast cities like New York and Boston, there is no heat index threshold for when a site is required to shut down, experts say. While Oregon has floated the idea of requiring work to halt once the temperature went above a certain level, there is nothing in place there either. 

In Boston last week, construction workers suffered through temperatures that led Mayor Kim Janey to declare a state of emergency, saying they needed the paycheck, The Boston Globe reported. In Oregon, workers were reportedly asked to push through in temperatures that reached above 110 degrees. 

Construction companies come up with their own methods of determining when it gets too hot to work.  

“There is no written rule," CNY’s Prude said. “If it is 90 degrees 100% humidity, or if someone gets sick or something, you gotta balance it. You gotta use your judgment.” 

CNY, which operates multiple sites with up to 400 to 500 workers per week, doesn't shut down in extreme heat. Instead, the company will more frequently use heat preventive measures, start work earlier to ensure that workers are out of the sun by the hottest part of the day, or maybe reschedule a workday to a weekend if it is simply too hot to work, he said.

"I have never, maybe once I can remember shutting the job down due to heat," Prude said. "I've shut it down due to winds, rain, ice."

Eastbound Construction CEO Alex Elkin at 20 Bruckner Blvd.

At Skanska, workers are limited from the number of hours they are able to work when it gets above a certain temperature, said Executive Vice President and General Manager Bryan Northrop, who is based in Boston. 

"[Something] we try to do is refrain from working folks who are out in those kinds of conditions overtime on a lot of jobs,” he said. "We will steer away from that in this type of weather." 

When temperatures climb toward or above 100 degrees, the site will only be a bit more efficient than shutting a site down for a day, said Elkin, who works with dozens of contractors and subcontractors. 

“These are men and women working with their hands … These aren't machines, these aren't robots,” he said. “So, it's important to sort of keep that in mind and to coordinate. It's not going to be the most productive day.” 

There is also no way to calculate anticipated loss in the way that companies in areas like New York City can account for other extreme weather conditions, Elkin said. 

“It's much easier to quantify the delays because of bad weather. If it's raining or snowing, the ironworkers can't work — it's too slippery and dangerous — so that's an easy binary thing to calculate,” he said. “The reality is even if you're not talking about pure efficiency, even for the morale of the workers, even in the name of decency and humanity, you can't have somebody working in the heat for too long … There's a limit that frankly is not that high.” 

As temperatures rise, the cost of construction in these areas could go up, either from lengthened timelines, additional heat mitigation measures or other unpredictable costs resulting from a worsening climate.

“It's a hard thing to quantify and how subcontractors are adjusting pricing based on it,” Elkin said. “I don't know of any subcontractors who were taking that particular issue and choosing any line items for it but honestly, they will probably need to start thinking about it.” 

Overall, the construction industry needs to adapt effectively, even if it means spending more, to keep its labor pool — still facing a painful shortage — safe from extreme heat.

"I can’t speak to specific data on worker, illness and fatalities from heat exposure, but I do know that is a major concern," said Cannon, head of safety for AGC, the national construction lobbying group. "Now it has been brought to the forefront, but it's something that contractors have to deal with each year. It has the potential to cause illnesses and, unfortunately, sometimes fatalities."