Preparing for Summer Work in the Heat in More Ways than One

Numerous factors and types of workers should go into consideration for heat prevention.

• By Michael Prewitt
• Jun 01, 2021

As we approach summer, there are positive signs for workers: the economy is steadily recovering as people get vaccinated and return to normal life, and legislation is before congress to update our country’s infrastructure. Plenty of opportunities are on the horizon, especially for construction workers.

One of the few downsides of this summer’s work will be the heat and the challenges it poses to worker health and safety. As the climate continues to warm (2020 was the fifth-warmest year on record according to the National Centers for Environmental Information), with no federal standards in place to appropriately manage heat stress, the responsibility for heat safety falls on each state or even on each individual company. Appropriate knowledge and proper tools can help companies make summertime a safe and productive time.

Heat-related injuries occur in just about every major working group that the U.S. Bureau of Labor Statistics tracks. In 2018, 3,120 workers missed at least one day of work due to environmental heat.

Two of the biggest contributors to that total were Construction and Transportation with around 370 and 820 workers affected. That’s a lot of days off work, which costs companies a significant amount of money. Using OSHA’s cost estimator and a six percent profit margin (close to average for construction), a single heat-related incident requires about $1.3M in sales to cover the direct and indirect costs of that incident. The most important fact about heat-related injuries is that they are almost entirely preventable.

Understanding the Human Reaction to Heat

Humans have an incredible ability to adapt to varying environmental conditions, yet the adaptation to heat takes time and varies by individual. Moving a worker from North Dakota onto a job site in southern Arizona will not be seamless and could cause a slowdown in productivity while that worker adjusts to the new climate. Acclimatization can take from two to three weeks when managed properly; if not effectively managed, the worker’s health and work site safety are at risk.  Appropriate heat acclimatization is accomplished by increasing one’s core body temperature 1°C for an hour each day. If your job requires workers to wear PPE, as most do, you need to slowly add 20 percent of PPE each day, working toward full worksite PPE.

If people are so adaptable, what makes dealing with heat such a complex problem? First, let’s look at how the body handles heat. As your core body temperature rises, the primary mode of cooling off is sweating. Blood flow is increased to the skin, water and electrolytes are expelled by the sweat glands and the evaporation of sweat is what cools the body down. This process is very efficient, as long as evaporation can occur, your activity level does not increase and there is adequate hydration. However, job sites are subject to their environments and productivity requirements, which means the body’s cooling process via sweating can be disrupted. Knowing how to manage that disruption will protect workers and maintain productivity.

Once a worker starts sweating on the job site in the heat, you need to be able to monitor him/her and track his or her vitals. Heart rate needs to increase during sweating in order to pump blood fast enough to get it to the skin to cool off the body. Muscles also require blood to get oxygen and other nutrients for proper function during work. This means the cardiovascular system is strained when working in the heat and getting blood everywhere it is needed. If a worker is sweating and maintaining a steady workload, eventually the fluid loss from sweating is going to be felt. The sweat loss will result in lower blood volume and pressure. In order to maintain physical activity for work and continue sweating to keep the body cool, the heart once again needs to beat faster. You can begin to see how this cycle can cascade into a state of peril if fluids are not replenished and rest from work is not taken.

The cardiovascular system is not the only vital function being disrupted during work in the heat. The nervous system is being impacted as well, decreasing a worker’s ability to complete his/her tasks as well as affecting cognitive ability. Similar to the cardiovascular system having to work harder in the heat, the nervous system also needs to work harder to accomplish the same muscle movement it did when it wasn’t hot. This makes work-related tasks harder and cognitive decision-making more difficult. To summarize, a worker experiencing heat stress is forcing his/her heart to work harder while the muscles are challenged to continue work and cognitive functions are dropping, making quick decisions dangerous.

Employing Heat Safety Strategies

Worker heat stress is a serious and complex problem. Heat safety strategies, while well intentioned, do not help every worker. Each individual worker experiences heat stress differently, so universal strategies are limited in benefitting everyone. Many factors contribute an individual’s response to one-size-fits-all heat-reduction techniques. Those factors include: age older than 35, psoriasis, cardiovascular disease, diabetes, prescription drugs for a variety of illnesses, over-the-counter drugs, nicotine, alcohol use and gender. Including all of these factors in heat protection strategies is a logistical challenge.

Companies are getting smarter, however, as they learn more about heat-related injuries and prevention techniques. Employing smart PPE to monitor their employees’ status throughout the work day is one method being adopted, allowing supervisors and safety managers to detect individual worker’s needs as they happen, without having to be right next to their team members, asking them how they feel and if they need a break and observing their behaviors.

With better tools to monitor their teams, heat stress and safety can more easily be integrated into the daily activities of construction, transportation, mining, utilities, manufacturing and many other industries that must manage under hot and humid working conditions. When combined with consistent education for both employees and supervisors, protecting workers from heat stress becomes a more effective part of the job. Smart PPE allows everyone to know when an individual needs to break, when to drink and how much to drink, when to stop working and rest in the shade.

Similar to smart, real-time information about individual workers and their heat stress, unique information about the jobsite climate and microclimate, which informs PPE requirements, is available through smart PPE. It may be 55 degrees Fahrenheit inside a mine, but if the worker has to put on intense PPE that traps heat and moisture, the microclimate is similar to a hot and humid summer day. If you only have a universal heat safety protocol, that employee may not get the attention he/she needs at the right time—when a heat injury is about to happen. The worker will keep pushing his/herself to the limit, resulting in serious health and safety outcomes.

There are several things companies can do to get their teams prepared for the hot summer season, including being educated on the symptoms of heat exhaustion and exertion heat stress, work/rest schedules, hydration practices and smart PPE. Workers should also understand the signs of heat stress and know where water stations and shade areas are located. These steps can prevent heat-related incidents and, at least, make them less severe.

In the meantime, off the job site, there has been legislation put forward in congress that would require OSHA to set federal standards for working in the heat. Only a handful of states currently have standards that address hot working environments. The bill has died twice in previous congresses and OSHA will have up to two years after it has passed to set the standards. This means there may be a long waiting period before standards can be applied to your jobsites. Regardless of legislative outcomes and timing, safety leaders and workers both need to pay attention to health and safety in hot environments. Human lives still depend on appropriate protocols, more education and continued advancements in heat health.

This article originally appeared in the June 1, 2021 issue of Occupational Health & Safety.